JP3449236B2 - Joint structure and joint method of steel segment - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a steel segment .
Relates joint hand method, lining of steel structures especially built the natural ground of the tunnel only a plurality of steel segments (lining)
Or a steel-concrete composite structure constructed by placing concrete as a secondary lining on the inside of a steel segment installed as a primary lining, and as a secondary lining. It is applied when lining with a lining body of steel / reinforced concrete composite structure constructed by arranging multiple reinforcing reinforcing bars in the installed concrete.

[0002]

2. Description of the Related Art As a method for lining the ground of a tunnel immediately after excavation, the applicant has so far constructed a method of constructing a steel-structured lining body by installing a plurality of steel segments in the ground of the tunnel. , A method of constructing a lining body of steel-concrete composite structure by installing multiple steel segments as the primary lining on the ground of the tunnel and placing concrete as the secondary lining inside it, We have developed a lining method for constructing a lining body of steel / reinforced concrete composite structure by arranging reinforcing bars in the concrete placed as the secondary lining on the inside of the segment.

As a method for efficiently and economically constructing a tunnel having a large cross section, the applicant of the present invention first constructs a rectangular tubular outer shell portion 30 as shown in FIG. A construction method for a large-section tunnel (MMST method) in which earth and sand in the outer shell 30 is excavated to construct a large-section tunnel A has also been developed.

At this time, the outer shell portion 30 excavates a plurality of single shield tunnels a (hereinafter referred to as "single tunnel a") in close proximity, and then joins the single tunnels a so as to be continuous in one space. It is constructed by continuously placing concrete 31 in it.

FIG. 8 shows an example of a steel segment used in the construction method of these tunnels. As shown in the figure, the steel segment 32 has a plurality of main girders 33 arranged in parallel in the circumferential direction of the tunnel. , Joint plates 3 at both ends of the main girder 33
4 are installed, and a plurality of vertical ribs 35 are installed between the adjacent main girders 33, 33 at predetermined intervals in the axial direction of the main girder 33 to form a rectangular grid frame body. It is formed by attaching a skin plate 36 to the natural side.

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

[0007]

However, in the method of bolting the joint plate 34 with the short bolts 37 as described above, transmission of bending stress and tensile stress in the joint portion is performed by the joint plate 34.
Since the stress is concentrated on the joint plate 34, the joint plate 34 is easily deformed as shown in FIG. 9 (b), so that the axial force of the short bolt 37 varies. There was a problem that a predetermined tensile force could not be transmitted.

Further, if the joint plate 34 is deformed in this way, there is a problem that it cannot fully fulfill its role as a lining body for waterproofing and maintaining the shape of the shield tunnel.

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 girders 33 are joined to the joint plate 38 and a plurality of high-strength bolts 39. Although high-strength bolt friction joining, etc., has also been studied, the axial force of the bolt varies due to the influence of construction load such as jack thrust after the steel segment 32 is installed, and the axial force of the bolt varies. 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 by the bending moment in the simple tunnel a and 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.

Further, these short bolts 37 are generally
When assembling the steel segment 32, the allowable tensile stress is 8
An initial introduction axial force of about 0% is introduced. Further, in the case of a large-section tunnel, in order for the short bolt 37 to secure a predetermined safety factor against the sectional force of the large-section tunnel, it is necessary to satisfy the following conditions.

The tensile force of the short bolt 37 must be within the design value when the single tunnel a is constructed. This is because when the short bolt 37 has a tensile force equal to or greater than the design value when the single tunnel a is constructed, the bolt tensile force becomes insufficient when the large cross section tunnel A is constructed. The initial axial force of the short bolt 37 should be almost constant for all bolts when the concrete 31 is placed . This is because if the initial introduction axial force of the short bolts 37 varies, the rigidity of each of the short bolts 37 varies, so that the proportion of the tensile force generated when the large-section tunnel A is constructed varies.

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

This is because the steel segment 32 is deformed under various construction loads (jack thrust, connection construction load, etc.) between the installation of the steel segment 32 and the placing of the concrete 31. And steel segment 32
This is due to the fact that while gradually deforming, it adapts to the ground surface.

This variation in axial force is caused by the concrete 31
There is no particular problem if the axial force can be introduced and adjusted again before placing the steel, but since there is a large variation in the torque value due to the influence of rust and water droplets, it took time to install the steel segment 32. It is not possible to reintroduce a constant axial force on the bolt later.

Further, in order to confirm that the tensile strength due to the cross-sectional force of the large cross-section tunnel A is ensured, the single tunnel a joined to form one continuous space is confirmed. It is necessary to grasp the tensile force acting on the short bolt 37 before placing the concrete 31, but when the steel segment 32 is assembled, an initial introduction axial force of about 80% of the allowable tensile force stress is introduced. Therefore, the tensile force acting on the short bolt 37 cannot be grasped.

Therefore, even if some short bolts 37 are subjected to a tensile force above the design value due to some load during construction, it cannot be dealt with. In this way, if one type of short bolt is used to deal with both the sectional force of the end tunnel of the simple tunnel and the sectional force of the large section tunnel, various problems as described above will occur. Quantitative quality assurance is not possible for bolt proof strength.

The present invention has been made to solve the above problems. The tensile strength of the joint bolts is quality and guaranteed, the steel segments can be securely and firmly joined to each other, and a high waterproofness can be maintained. An object of the present invention is to provide a joint structure for a steel segment and a joint method therefor.

[0019]

In order to solve the above problems BRIEF SUMMARY OF THE INVENTION joint method of a steel segment engaging Ru to the present invention, structure
In a joint structure of steel segments having a main girder and a joint plate extending in the tunnel circumferential direction and axial direction respectively as a constructional premise, the main girder is joined by a plurality of short bolts penetrating the joint plate in the tunnel circumferential direction. A plurality of high-strength bolts that penetrate the plate and the tunnel in the axial direction are used to join them.

According to the first aspect of the present invention, there is provided a steel segment joint method , comprising a main girder and a joint plate extending in a circumferential direction and an axial direction of a tunnel, respectively. Assemble steel segments by joining with multiple short bolts that pass through the circumference of the tunnel , and then construct
When it receives a load, it gradually deforms and the bolt axial force
There is no influence on fluctuations, and the segment is sufficiently on the ground surface.
After fitting in , the main girders are frictionally joined to each other by a plurality of high-strength bolts penetrating in the axial direction of the joint plate and the tunnel.

According to a second aspect of the present invention, there is provided a steel segment joint method, wherein a single shield tunnel is lined with a steel segment and is dug, and then concrete is cast in the single shield tunnel to a predetermined thickness to form the tunnel. At the time of construction, in the method of joining steel segments that join steel segments together, when digging a single shield tunnel, steel segments are joined by a plurality of short bolts that penetrate the steel segments in the circumferential direction of the tunnel to form a steel segment. Assembled and then constructed
When the load is applied, it gradually deforms and the bolt axial force changes.
Motion is not affected and the segment is
Then, before the concrete is placed, the steel segments are friction- bonded to each other with a plurality of high-strength bolts penetrating in the axial direction of the joint plate and the tunnel.

According to a third aspect of the present invention, there is provided a steel segment joint method, wherein after digging a plurality of single shield tunnels while lining them with steel segments, concrete is placed in the single shield tunnel to form an outer shell portion. When constructing, and then excavating the earth and sand in this outer shell to construct a tunnel of large cross section,
In a steel segment joint method for joining steel segments to each other, at the time of excavation of a single shield tunnel, steel segments are joined by a plurality of short bolts penetrating in the circumferential direction of the tunnel to assemble a steel segment, and then construction
When it receives a load, it gradually deforms and the bolt axial force
There is no influence on fluctuations, and the segment is sufficiently on the ground surface.
After fitting in, before placing concrete (or just before placing concrete), steel segments are joined with a plurality of high-strength bolts that penetrate the joint plate and the tunnel in the axial direction.

According to a fourth aspect of the present invention, there is provided a steel segment joint method according to the second or third aspect, wherein the contact surface between the main girder and the joint plate is formed into a rough surface or an uneven shape. The method for joining steel segments according to claim 5 is the method according to claim 2, 3 or 4.
In, 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 in which a plurality of steel segments 1 are provided on the ground surface of a large-section tunnel A in the circumferential direction and the axial direction of a single tunnel a. They are installed adjacent to each other and joined to each other.

At this time, in particular, the steel segments 1 adjacent to each other in the circumferential direction of the unitary tunnel a are joined to each other by high-strength bolt friction joining with a joint plate 2 and a plurality of high-strength bolts 3 as shown in FIG. It is joined by bolt joining with the short bolt 4. However, these joints are not simultaneous.
As will be described later, first connect the joint plate 7 to the circumference of the tunnel.
Steel segment by connecting with a plurality of short bolts 4 that penetrate in the direction
Assembling the grate 1 and then receiving the load during construction
It gradually deforms and has no effect on the fluctuation of bolt axial force.
The main girder after the segment 1 has fully adjusted to the ground surface.
5 through the joint plate 2 and the tunnel axial direction
The high-strength bolts 3 are friction-bonded with each other.

FIG. 2 (a) shows an example of a steel segment used here, and as shown in the drawing, a plurality of main girders 5 extend in parallel in the circumferential direction of the unitary tunnel a and are adjacent to each other. A plurality of vertical ribs 6 are attached between the main girders 5 and 5 at predetermined intervals in the axial direction of the main girder 5, and a joint plate 7 and a reinforcing plate 8 are attached between the 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 body 9 formed in a rectangular shape from these members. Note that these members are joined to each other by welding or bolt joining.

Each of the main girder 5, the vertical ribs 6 and the joint plate 7 is formed into a strip plate having a predetermined beam formation (height). Further, a plurality of bolt holes 11 for fastening the high-strength bolts 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 formed at predetermined intervals in parallel in the axial direction of the main girder 5 and the joint plate 6, respectively. The vertical holes 13 are located 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 freely slide in the axial direction of the main girder 5. There is.

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 ribs 6 are reinforced by the reinforcing ribs 6a as necessary so as to have sufficient strength as a reaction force receiving the propulsion reaction force of the shield machine for excavating the single tunnel a, and are optimal between the main girders 5 and 5. It is installed at regular intervals.

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

Then, the short bolt 4 is fastened to the bolt hole 11 of the joint plate 7. Further, 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.

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

At this time, the contact surface between the end portion of the main girder 5 and the joint plate 2 may be formed into a rough surface, or as shown in FIG.
As shown in the drawing, the friction coefficient of the contact surface can be remarkably increased by forming a large number of extremely small uneven portions 14 on the contact surface.

Further, as illustrated in FIG. 3 (a), (b) , by two joint plates 2 formed thinner by the end of the main girder 5 to their respective joint, the workability It is possible to improve and it is possible to easily absorb the error in the construction condition of the segment joint.

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

Further, in particular, in the case of a large cross-section tunnel as shown in FIG. 5, in order to construct the outer portion 17 of the steel / reinforced concrete composite structure, a plurality of steel segments 1 are dug while lining, and Reinforcing bars 16 are arranged in a single tunnel a that is continuously joined to one space,
After that, concrete 15 is placed. And
The inner sediment of the outer shell 17 thus formed is excavated.

In the case of constructing the large cross-section tunnel A as shown in FIG. 5, there is also a case where a steel / concrete composite structure is used without particularly reinforcing bars. Next, a method for joining steel segments according to the present invention having such a configuration will be described (see FIGS. 6 (a) to 6 (e)).

In the tail portion 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 that time, the steel segments 1 adjacent to each other in the circumferential direction of the tunnel
As shown in FIG. 6 (b), the joint plate 7 is closely attached so that no gap is generated, and both bolt holes 12 are aligned. Next, the short bolts 4 are fastened to the bolt holes 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 the steel segment, the steel segment 1
Is gradually deformed by being subjected to various loads during construction after assembly, and the bolt axial force fluctuates, so these effects are eliminated, and after the segment has fully fitted to the ground surface,
The main girders 5 are friction-bonded to each other by the joint plate 2 and the plurality of high-strength bolts 3, respectively.

The joint plate 2 is a vertical hole 1 of one joint plate 7.
3 through the vertical hole 13 of the other joint plate 7 and bridge between the ends of both main girders 5. Then, the bolt hole 11 of the main girder 5
The high-strength bolt 3 is fastened to the bolt hole 2a 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 placed.
It is desirable to fasten just before placing the steel because it is not affected by the load during construction and the steel segment 1 fits well into the ground, and the subsequent deformation is almost stopped.

Further, when the high-strength bolt 3 is fastened, it is possible that 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 against such a case, when the steel segment 1 is installed (assembled), the main girders are temporarily joined with bolts 2a of the joint plate 2 and the bolt holes 11 of the main girder 5 (not shown). The five are temporarily joined together, the temporary joining bolt is pulled out when the concrete 15 is placed, and then the high-strength bolt 3 is fastened.

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

There is also a method in which some of the bolt holes 11 and 2a are initially formed 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 segment 1, and in the case of high-strength bolt friction welding, it is not possible to make large bolt holes in terms of quality. Since assembly accuracy is required, forming a bolt hole at the time of fastening a high-strength bolt can significantly improve the installation accuracy. In addition, high waterproofness of the joint can be secured.

Further, as shown in FIG. 3, by joining the ends of the main girders 5 with the two thinly formed joint plates 2, it becomes easier to deal with the error of the joint portion. .

When the lining body is constructed with only the steel segment 1, the construction is completed, but the lining body is made of steel.
When using a concrete composite structure, the structure shown in FIG.
As shown in (c), concrete 15 is cast inside the steel segment 1 to a predetermined thickness, and when a steel / reinforced concrete composite structure is to be formed, reinforcing steel bars 16 are arranged in the concrete 15.

Further, in the case of a large cross section tunnel as shown in FIG. 5, a single tunnel a which is lined with a plurality of steel segments 1 and joined so as to be continuous in one space a
Reinforcing bars 16 are laid inside, and then concrete 15
And the outer shell body 17 is constructed. Then, the large-section tunnel A is constructed by excavating the earth and sand in the outer shell portion 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 the stress particularly generated in the large-section tunnel.

[0050]

The present invention has the configuration described above,
Especially when constructing a large-section tunnel, the bolt that receives tensile force due to its sectional force in the large-section tunnel is completely separated from the short bolt that receives tensile force due to its sectional force in the single-section tunnel, so that the bolt has a large-section tunnel. Since it can be confirmed that the tensile strength due to the cross-sectional force of the large cross-section force is confirmed, it is possible to quantitatively guarantee the quality of the bolt strength in the large-section tunnel, which can reduce the stress generated in the large-section tunnel. On the other hand, a joint structure having a reliable tensile strength can be obtained.

Further, with respect to the sectional force of the large section tunnel,
By making the joint part of the steel segment a joint of high strength bolt friction joint with high joint rigidity, it has excellent crack prevention and toughness, especially steel / concrete composite structure or steel / reinforced concrete composite structure that is strong against repeated load during earthquakes. A large-section tunnel with a structure can be constructed.

Further, when assembling the steel segment, only the short bolts need to be fastened. Therefore, after confirming construction errors such as manufacturing error and assembly error of the steel segment, the high strength bolt is fastened. By forming a bolt hole for this, the construction accuracy can be improved.

In particular, in the case of high-strength bolt friction welding, since a large bolt hole cannot be formed in terms of quality, a high degree of assembly precision is required. Can be significantly improved. In addition, high waterproofness of the joint can be secured.

[Brief description of drawings]

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

2A and 2B show a joint between steel segments adjacent to each other in the circumferential direction of the tunnel, 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 in the circumferential direction of the tunnel showing a joint portion between main girders.

FIG. 3 is a perspective view showing a joint between steel segments adjacent to each other in the circumferential direction of the tunnel, FIG. 3A is a perspective view showing a state before joining, and FIG. 3B is a perspective view showing a state after joining.

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

[Fig. 5] Fig. 5 shows a large-section tunnel constructed with a composite structure of steel and reinforced concrete, (a) is its sectional view, (b) is a partial perspective view of the lining body, and (c) is a sectional view in the axial direction of the tunnel. Is.

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

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

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

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

FIG. 10 is a cross-sectional view showing a joint made of high-strength bolts of steel segments adjacent to each other in the circumferential direction of the tunnel.

[Explanation of symbols]

1 Steel segment 2 Joint plate 3 high strength bolts 4 short bolts 5 main girders 6 vertical ribs 7 Joint plate 8 Reinforcement plate 9 Lattice frame 10 skin plate 11 bolt holes 12 bolt holes 13 vertical holes 14 uneven parts 15 concrete 16 Reinforcing rebar 17 Outer part

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Claims (5)

(57) [Claims] 1. A joint method of a steel segment having a circumferential and axial directions extending respectively the main girder and the joint plate of the tunnel, first by joining a plurality of short bolts passing through the fitting plate in the circumferential direction of the tunnel Assemble the steel segments and
After that, the load during construction will gradually deform and
The influence on the fluctuation of axial force is eliminated, and the segment is solid.
From at sufficiently familiar to the surface, high strength ball in a plurality of high strength bolts passing through the main beam each other in the axial direction of the joint plate and the tunnel
A method for joining steel segments, characterized in that it is made by friction welding. 2. The steel segments are joined to each other when the single shield tunnel is lined with the steel segments and is dug, and then concrete is cast in the single shield tunnel to a predetermined thickness to construct the tunnel. In the method of joining steel segments to assemble, the steel segments are assembled by joining the steel segments with a plurality of short bolts penetrating in the circumferential direction of the tunnel during the excavation of the single shield tunnel ,
After that, it gradually deforms due to the load during construction,
The influence on the axial force fluctuation is eliminated, and the segment is
The steel segment is characterized by performing high-strength bolt friction welding between the steel segments with a plurality of high-strength bolts penetrating in the axial direction of the joint plate and tunnel before pouring concrete. Joint method. 3. A plurality of single shield tunnels are lined with steel segments to be excavated, then concrete is placed in the single shield tunnel to construct an outer shell portion, and then earth and sand in the outer shell portion. When constructing a large-section tunnel by excavating a steel segment, in the joint method of steel segments that join steel segments together, when a single shield tunnel is dug, a plurality of short segments that penetrate the steel segments in the circumferential direction of the tunnel are pierced. Assemble the steel segments by bolting them together and
After that, the load during construction will gradually deform and
The influence on the fluctuation of axial force is eliminated, and the segment is solid.
A method for joining steel segments, wherein the steel segments are joined to each other with a plurality of high-strength bolts penetrating in the axial direction of the joint plate and the tunnel before the concrete is poured, after the steel segments are sufficiently fitted. 4. The method of claim 2 or the contact surface between the main beam and the fitting plate and forming a rough or uneven
3. The method for joining steel segments according to item 3 . 5. A portion of the bolt holes for fastening the high strength bolt is formed during manufacture of the steel segment, claim 2, characterized in that formed at the time of fastening the high-strength bolts the rest or
Or the method of joining steel segments according to item 4 .