JP4051144B2 - Joint structure and joining method of single shields in the outer shell leading tunnel method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention belongs to the technical field of an outer shell advanced tunnel method for constructing a super large section tunnel by a shield method with a small cross section, and more specifically, relates to a joint structure and a joining method for single shields forming an outer shell.
[0002]
[Prior art]
As shown in FIG. 6, the outer shell portion of the tunnel is formed by a chain of single shields K by the shield method with a small cross section, as shown in FIG. A so-called outer shell leading tunnel construction method has been proposed in which the single body shields K are joined together in series and then excavated to complete the inner main body tunnel T (see, for example, the construction method described in JP-A-7-224587). ). According to this outer shell leading tunnel construction method, it is possible to easily construct an ultra-large-section rectangular tunnel having a length × width of about 20 m × 30 m without further excavation. Incidentally, the size of each single-piece shield K is about 2.5 m × (5.0 to 7.5 m) in length × width.
[0003]
By the way, when constructing the outer shell preceding tunnel construction method, an interval L ₁ or L ₂ is secured between the single shields K, K adjacent to each other in the vertical and horizontal directions so as not to interfere with the propulsion of the shield machine. Construction is proceeded. Therefore, after each single shield K is constructed, a step of excavating the soil of the interval portions L ₁ and L ₂ and integrally joining them in series is performed.
[0004]
However, the adjacent single shields K, K constructed as described above cause large or small construction errors in the vertical direction, the horizontal direction, and the axial direction as illustrated in FIG. For this reason, each joint structure must be allowed to be constructed on the assumption of the construction error.
[0005]
Therefore, conventionally, as a joint structure for joining the single shields, for example, as shown in FIG. 8, a joining method of a reinforced concrete structure in which a D51 (outer diameter is 51 mm) rebar S is arranged long has been studied.
[0006]
[Problems to be solved by the present invention]
However, in the case of the conventional joining means of the reinforced concrete structure as shown in FIG. 8, the following problems are pointed out.
[0007]
(1) Since the reinforcing bar S is arranged inside the single shield K, the effective height of the tensile reinforcing bar is reduced by the digit height of the steel shell 1. As a result, the amount of rebar S increases to secure a predetermined bending moment, so it cannot be said to be a rational and economical joint structure. Incidentally, the arrangement and the amount of the reinforcing bar S are as illustrated in FIGS. 9A and 9B.
[0008]
(2) In order to transmit the reinforcing bar stress of the joint to the steel shell body, the fixing length of the reinforcing bar S to the single shield side (refer to the symbol W in FIG. 8) becomes long, and it is adjacent to the horizontal direction in FIG. May intersect with mating joints. Even if they do not intersect, the long rebar S protrudes inside the single shield K. As a result, the assembling work of the rebar S is hindered, and there are various restrictions on the use of the internal space of the single shield K. This hinders work and transportation of materials.
[0009]
{Circle around (3)} D51 rebar S of several m in length, that is, one to three rebars must be assembled in a narrow single shield internal space, and the rebar S assembly work is extremely difficult.
[0010]
Therefore, the object of the present invention is to join the steel shell main girders of adjacent single shields directly and simply by bolts to ensure the transmission of stress, and the construction error between the single shields or joints. There is no need to survey at all even if the width is changed, and it is possible to respond appropriately and to provide a reasonable joint structure and joining method with excellent flexibility and workability.
[0011]
A different object of the present invention is that the effective utilization rate of the internal space of the single shield is high, and it is possible to use a transport vehicle (steel vehicle), etc., and it is easy to perform parallel work with other types of work, and the construction period is greatly shortened. It is providing the junction structure and joining method which can aim at.
[0012]
[Means for Solving the Problems]
As a means for solving the above-mentioned problem, the joint structure between the single shields in the outer shell preceding tunnel method according to the first aspect of the present invention is that the outer shell of the super large cross section tunnel is connected to the single shield K having a small cross section. In the outer shell advanced tunnel construction method formed in step 1, after constructing the adjacent shields K and K with a space that does not hinder the propulsion of the shield machine , excavate the soil in the space portions L ₁ and L _2. Thus, the main girders 2 and 2 of the steel shells 1 and 1 constituting the single shield are joined together by bolts 6 and nuts 7 via a plate-like end plate 3 made of cast steel and a spherical washer 5 made of cast steel. A joint structure,
A plurality of main girders 2 of the steel shell 1 constituting the single shield K are provided in parallel in the circumferential direction of the super large cross-section tunnel, and are thick and rigid between the main girders 2 and 2 at the corners of the main girder 2. The end plate 3 made of high cast steel is welded and joined to the main girder 2 in a direction perpendicular to the end, and the adjacent single shields K and K are disposed so that the end plates 3 and 3 face each other.
The outer peripheral surface 5b with the exception of the nut contact face 5a of the washer 5 in the sphere-shaped, a rotatable corresponding to the angle θ to the displacement of the main girder 2,2 unitary shield K, K of the steel shell 1, 1 adjacent is formed in a spherical shape, the said end plate 3, a plurality of bolt holes 4, the washer abutting portion of the bolt holes 4 in the receiving portion 4a of the spherical concave for receiving the outer circumferential surface 5b of the washer 5 in the spherical is formed, the receiving portion 4a is formed in the pores of the diverging shape of an angle that allows the displacement of the main girder 2 of the steel shell 1 theta as a base point is received in the receiving portion 4a of the end plate 3 Following and a bolt 6 through the washer 5 of spherical shape, characterized in that it is joined by a nut 7 which is screwed to the bolt 6.
[0013]
The method for joining the single shields in the outer shell leading tunnel method according to the second aspect of the present invention is the outer shell leading tunnel method in which the outer shell of the super large section tunnel is formed by a chain of small section single shields K. shield K, drilled the interval portions L _1, L ₂ of the soil after construction to ensure the spacing is no problem in the propulsion of the shield machine during K between, the steel shells 1,1 which constitute a unitary shield It is a method of joining the main girders 2 and 2 with a bolt 6 and a nut 7 using a plate-like end plate 3 made of cast steel and a spherical washer 5 made of cast steel ,
A plurality of main girders 2 of the steel shell 1 constituting the single shield K are provided in parallel in the circumferential direction of the super-large cross section tunnel, and are thick and rigid between the main girders 2 and 2 at the corners of the main girder 2. An end plate 3 made of cast steel is welded and joined to the main girder 2 in a direction perpendicular thereto, and the end plates 3 and 3 of the adjacent unitary shields K and K are provided to face each other;
A rotatable outer peripheral surface 5b with the exception of the nut contact face 5a of the washer 5 in the spherical shape, the adjacent single shield K, the angle θ corresponding to the displacement of the main girder 2,2 of the steel shells 1,1 K Forming into a spherical shape,
The end plate 3, a plurality of bolt holes 4, formed in the receiving portion 4a of the spherical concave washer abutting portion of the bolt hole 4 is rotatably receiving the outer peripheral surface 5b of the washer 5 in the spherical, followed by Forming a hole having a divergent shape with an angle θ that allows displacement of the main girder 2 of the steel shell 1 with the receiving portion 4a as a base point;
Through a bolt 6 in the bolt holes 4 corresponding end plate 3 each other to the face, after being fixed to the receiving portion 4a through the washer 5 in the spherical to the bolt end, the spherical shape is screwed a nut 7 It is characterized by being fastened and joined to the nut contact surface 5a of the washer 5.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
The joint structure between the single shields in the outer shell preceding tunnel construction method according to the invention described in claim 1 is the case where the adjacent single shields K and K are joined together as shown in the embodiment in FIGS. In particular, the main girders 2 and 2 of the steel shell 1 constituting the unitary shield K are joined together by bolts 6 and nuts 7 via the end plate 3 and the spherical washer 5.
[0015]
The single shield K in the present embodiment has a tunnel height of 2500 mm, and its steel shell 1 is configured by arranging four main girders 2 in parallel (see FIG. 2). Is 1200 mm. The steel shell 1 is generally composed of a skin plate 1a and a main girder 2 (see FIG. 5).
[0016]
FIG. 1 shows a joint structure corresponding to a vertical position shift (shift angle θ) between single shields K, K (steel shells 1, 1) adjacent to the left and right. In the present embodiment, the case is shown in which the joint interval L ₂ is about 200 mm, the generated positional deviation L ₃ is about 100 mm, and the deviation angle θ is about 12 °.
[0017]
As shown in FIG. 3, the spherical washer 5 is made of cast steel, penetrates a bolt hole 5d having a diameter of 38 mm through the center of a sphere having a radius of 36 mm, and has a thickness of 44 mm from the flat nut seat surface 5a. It is formed in a hemispherical shape. Therefore, the spherical washer 5 is configured to be rotatable with respect to an angle θ (where θ ≦ 12 °) corresponding to the displacement of the steel shell main girders 2 and 2 of the adjacent single shields K and K. (See FIG. 1).
[0018]
On the other hand, the end plate 3 is also made of cast steel, and is formed in a plate shape that is thick (thickness 80 mm) and has high rigidity. The end plate 3 has a size of 355 × 1200 mm in length × width, and is the same between the main girders 2 and 2 at the corners of the four main girders 2 of the steel shell 1 shown in FIG. It is welded and joined to the main girders 2 in a direction perpendicular to each other, and is provided in an arrangement in which the end plates 3 and 3 of the adjacent single shields K and K face each other . In order to make the welding with the main beam 2 easy and reliable, it is preferable to provide a projection in advance at the joint portion of the main plate 2 in the end plate 3 (not shown).
[0019]
A necessary number of bolt holes 4 are formed in the end plate 3. As shown in FIG. 2, a total of 18 bolt holes 4 are provided along the main girder 2 at six locations on both sides thereof. The washer contact portion of each bolt hole 4 is a spherical surface having substantially the same diameter as the outer diameter of the spherical washer 5 so as to receive the spherical outer peripheral surface 5b of the spherical washer 5 as shown in FIG. It is formed in a concave receiving portion 4a. The bolt hole 4 has a diameter of 50 mm at the receiving portion 4a, and is formed in a divergent shape (conical shape) that allows the bolt 6 to be inclined with respect to the positional deviation angle θ of the steel shell main beam 2.
[0020]
Next, based on the above configuration, a method for joining single shields in the outer shell preceding tunnel construction method according to the invention described in claim 2 will be described. As described above, the steel shell main girders of the adjacent single shields are suitably implemented as a method of joining with the bolt 6 and the nut 7 using the end plate 3 and the spherical washer 5.
[0021]
As shown in FIG. 1, a bolt 6 (φ = 36 mm) having a predetermined length is passed through the corresponding bolt holes 4 and 4 of the end plates 3 and 3 of the adjacent single shields K and K, and both end portions of the bolt 6 are passed. To the concave receiving portion 4a through the spherical washer 5. Regardless of the position deviation L3 between the steel shell main girders 2 and 2 to be joined by passing the bolt 6 and the deviation angle θ, the spherical washer 5 fits in the receiving portion 4a and is measured at the construction site. It is useless at all.
[0022]
Thereafter, a nut 7 (outer diameter 61 mm) is screwed into the screw portion 6a at the end of the bolt 6, and the nut 7 is strongly tightened to the nut abutting surface 5a of the spherical washer 5 to complete the joining operation. Since the nut 7 and the spherical washer 5 and the bolt 6 and the thick and rigid end plate 3 directly join the steel shell main girder 2, the stress transmission between the adjacent main girder 2 and 2 of the single shield is reliable. To be done.
[0023]
Moreover, the single-piece shield K in which the spherical washer 5 is displaced not only in the vertical direction illustrated in FIG. 1 but also in the horizontal and axial directions of the steel shell main girder 2 in all aspects. , K is freely adaptable to K, and has the flexibility and flexibility to transmit the stress between steel shell main girders reliably. In the case of the above embodiment, since the distance between the steel shell main girders 2 and 2 is 400 mm, the spherical washer 5 is attached to the end plate even if an error of 200 mm at maximum occurs in any of the vertical direction, the horizontal direction, and the axial direction. The bolt 6 is arranged in the proper direction by being rotated in the position 3, and the stress transmission between the steel shell main girders 2 and 2 is ensured.
[0024]
Further, as described above, the joint part between the main girders 2 and 2 of the single shield has a simple structure in which the joint 6 is joined by the bolt 6 and the nut 7 via the spherical washer 5 and the end plate 3. No obstacles occur in the interior space of the apparatus, and it is possible to secure a large passage of people and a material conveyance path within the single shield K.
[0025]
[Effects of the invention]
The joint structure and joining method of the single shields according to the first and second aspects of the invention include a steel shield main girder of a single shield adjacent to each other by bolts and nuts via a spherical washer and a thick end plate. They are directly and simply joined together to ensure stress transmission and provide a high-quality single shield.
[0026]
Moreover, for construction errors between single shields or changes in the joint width, bolts can be placed in the proper direction with a rotatable spherical washer, so it is necessary to measure different construction errors individually at each construction site. There is no progress, and a dramatic improvement in work efficiency is achieved.
[0027]
In addition, the effective use rate of the internal space of the single shield is high, and it can be used by a transporter (steel car), etc., and can be easily operated in parallel with other types of work, contributing to a significant reduction in the work period. .
[Brief description of the drawings]
FIG. 1 is a front view showing a main part of a joint structure according to the present invention.
2 is a back view of the end plate as viewed in the direction of arrows AA in FIG.
FIG. 3 is a side view showing a spherical washer and a front view partially broken.
4 is an enlarged cross-sectional view showing an end plate portion of FIG. 1. FIG.
FIG. 5 is a cross-sectional view showing the structure of a steel shell.
FIG. 6 is a cross-sectional view showing an embodiment of the outer shell leading tunnel method.
FIG. 7 is an explanatory diagram of a positional shift between adjacent single shields.
FIG. 8 is an explanatory diagram of a conventional technique for joining adjacent single shields.
FIGS. 9A and 9B are diagrams for explaining the arrangement of conventional joining reinforcing bars. FIGS.
[Explanation of symbols]
K Single shield 1 Steel shell 2 Main girder 3 End plate 4 Bolt hole 4a Receiving part 5 Spherical washer 5a Nut contact surface 5b Outer peripheral surface 6 Bolt 7 Nut θ Position shift angle

Claims (2)

In the outer shell leading tunnel construction method in which the outer shell of a super-large-section tunnel is formed by a chain of single-section shields with a small cross-section, the gap is set after securing an interval that does not hinder the propulsion of the shield machine between adjacent single shields. It is a joint structure in which the main girder of the steel shell constituting the single shield is joined with bolts and nuts via a cast steel plate-like end plate and a cast steel spherical washer by excavating the soil of the part Yes,
The main girder of the steel shell that constitutes the single shield is provided in parallel in the circumferential direction of the super large section tunnel, and a thick-walled and rigid cast steel end plate is provided between the main girder at the corners of the main girder. It is welded and joined to the main girder in a direction perpendicular to the main girder, and it is provided in an arrangement where the end plates of adjacent single shields face each other,
The outer peripheral surface except the nut abutment surface of the washer of the spherical shape is formed in a rotatable spherical shape corresponding to an angle to the main girder of the positional deviation of the steel shell of the adjacent single shield, the end plate has a plurality bolt holes are formed a washer abutting portion of the bolt hole in the receiving part of the spherical concave for receiving the outer peripheral surface of the washer of the spherical, the main girder of the positional deviation of the steel shell as the base of the receptacle and subsequently is formed in the pores of the diverging shape of an angle to allow, characterized in that a bolt through the washer spherical shape received in the receptacle of the end plates are joined by a nut screwed to the bolt The joint structure of single shields in the outer shell leading tunnel method. In the outer shell leading tunnel construction method in which the outer shell of a super-large-section tunnel is formed by a chain of single-section shields with a small cross-section, the gap is set after securing an interval that does not hinder the propulsion of the shield machine between adjacent single shields. It is a method of excavating the soil of the part, joining the main girders of the steel shell constituting the single shield with bolts and nuts using a cast steel plate-like end plate and a cast steel spherical washer,
A plurality of main girders of the steel shell constituting the single shield are provided in parallel with the circumferential direction of the super large section tunnel, and a thick and rigid cast steel end plate is connected between the main girders at the corners of the main girder. Welded in a direction perpendicular to the main girder, and provided in an arrangement where the end plates of adjacent single shields face each other,
The outer circumferential surface except the nut abutment surface of the washer of the spherical shape, to form a rotatable spherical shape corresponding to an angle to the main girder of the positional deviation of the steel shell of the adjacent single shield,
The end plate, a plurality of bolt holes, the washer abutting portion of the bolt hole is formed in the receiving portion of the spherical concave rotatably receiving the outer peripheral surface of the washer of the spherical, as a base point to the receiving portion Following Forming a hole with a divergent shape at an angle that allows displacement of the main girder of the steel shell;
Through a bolt into the corresponding bolt holes of the end plates between which the face, after being fixed to the receptacle through a washer of said spherical in its bolt end, tightening the nut contact surface of the washer of the spherical shape by screwing nuts Joining,
A method of joining single shields in the outer shell advanced tunnel method characterized by

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