JP2017106272A - Tunnel support and method of constructing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tunnel support and a method of constructing the same that can complete construction efficiently in a short time.SOLUTION: A tunnel support 10 comprises at least two curved divided supports 1, 1, each of which comprises a pin insertion part 3 at a curved inner side of an end 1a coupled to the other divided support 1. Pin insertion parts 3, 3 of the divided supports 1, 1 to be coupled are positioned, a coupling pin 5 is inserted into both the pin insertion parts 3, 3, and when the divided supports 1, 1 are spread around the coupling pin 5 as a fulcrum, end faces 2, 2 of the divided supports 1, 1 abut on each other to form the tunnel support.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a tunnel support used in a mountain tunnel or the like and a construction method thereof.

  In the construction of a mountain tunnel, after excavating the ground by mechanical excavation, etc., concrete is quickly sprayed onto the inner wall of the tunnel with a spraying robot, etc. By building steel supporters of steel at the specified pitch on the surface of the shotcrete, the tunnel space is stabilized while preventing the collapse of the ground and the skin. More specifically, the above concrete spraying is the primary spraying, and after the steel support is built, the steel support is involved and the concrete is sprayed again as the secondary spraying. If necessary, the tunnel is reinforced by driving rock bolts into the ground.

  H-shaped steel is generally used for steel support, and two split supports that are divided symmetrically with respect to the tunnel center are built in, and the H-shaped steel web is connected at the connection point of both split supports. A tunnel support work is being constructed with two bolts on the left and right sides.

  If the tunnel cross section is large or the tunnel cross section is complicated, the left and right split support works are further divided into two or more parts, and the connection points of each split support work are bolted together, so that the tunnel support works May be constructed.

  The tunnel support work is carried by transporting the divided support work to the tunnel in the specified position with the transport carriage. For example, the split support work is installed while holding the split support work at the gripping part of the elector device. This is done by combining.

  However, it takes time to build a plurality of divided support works, to maintain the built-in posture, and to join the bolts between the divided support works. Especially, the bolt connection takes time and effort. There is a problem in terms of construction safety because such long-time work is performed in the vicinity of an unstable face.

  Here, in Patent Document 1, the upper end portion of the tunnel support material is substantially the same shape as the outer peripheral shape of the upper end contact surface, and the inner cross-section that can be smoothly inserted into the upper end portion of the other support material. A connection structure for a tunnel support material is disclosed, which includes a sheath-like connection material having an upper end portion of the tunnel support material and is connected to each other by inserting the upper end portion of the tunnel support material into the inner space of the tunnel support material. .

JP 2000-045695 A

  According to the connection structure of the tunnel support material described in Patent Document 1, the tunnel support material can be easily and reliably connected without complicated work such as bolt fastening, and the heavy equipment is used for the connection work. It is said that work can be performed only with mechanical power such as. However, it is actually not easy to fit the upper ends of the two tunnel support members from the right and left ends of the sheath-like connecting material, and it does not solve the above-mentioned problem that the tunnel support work takes time. .

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a tunnel supporting work that can be efficiently constructed in a short time and a construction method thereof.

  In order to achieve the above object, the tunnel support according to the present invention includes at least two curved split supports, and each split support has a pin insertion portion on the inner side of the end connected to the other split support. When the pin insertion part of each divided support to be connected is aligned, the connection pin is inserted into both pin insertion parts, and each split support is expanded with the connection pin as a fulcrum The end surfaces of each divided support work are formed in contact with each other.

  In the tunnel support of the present invention, the split support works made of two curved H-shaped steels are connected by connecting pins inside the curved portions of their end portions, so that the split support works are closed to the construction site. In the construction site, the tunnel support work is formed efficiently and quickly by expanding the split support work with an erector device etc. and bringing both end faces into contact with each other at the construction site. It is.

  Each split support is connected by a connecting pin inside the end curve, and the end faces are in contact with each other, but earth pressure etc. acts from the tunnel wall outside the formed tunnel support Thus, an axial force (compression force) acts in the axial direction of the tunnel support work, and the divided support works are integrated by this axial force, and the tunnel support work becomes independent.

  Here, “at least two split support works” means that the tunnel support work is formed from two split support works, or from three or more split support works due to the relationship between the tunnel cross-sectional dimensions and the tunnel cross-sectional shape. It means to include the case where it is formed. For example, in a form in which a tunnel support is formed from two split support works, one connection point by two split support works (usually there is a connection place at the center position by two split support works of the same shape) It is connected via a pin, and at the construction site, the end surfaces of each divided support are in contact with each other at one connection location to form a tunnel support. Further, for example, in a form in which a tunnel support is formed from four divided support works, three connection points by the four split support works are connected via a connection pin, and at the construction site, each split support work is performed at three connection points. The end surfaces of the two come into contact with each other to form a tunnel support.

  Further, the “curved shape” means a shape along the cross-sectional shape of a tunnel composed of one or a plurality of curvatures, and the shapes are various. Since each divided support is connected to each other via a connecting pin on the curved inner side of the end (position inside the curved shape), the end surfaces are brought into contact with each other when the divided support is spread, and the curved shape Tunnel support works can be formed.

  In addition, it is preferable that a steel plate is welded or the like to an end portion connected to another split support in the split support made of H-shaped steel or the like. Since the end surfaces made of the two split support plates come into contact with each other, it is possible to effectively transmit the axial force generated by the action of earth pressure or the like.

  When the tunnel support of the present invention is transported to the construction site, the divided support can be closed without being separated via the connecting pin. It can be transported without interfering with the work. In addition, since the plurality of divided support works are connected to each other, the transport work can be performed more efficiently than when the separated split support works are sequentially transported.

  In addition, for example, the tunnel support work is gripped by the grip part of the elector device and positioned at the construction site, and the split support work is expanded by operating the elector device to form the tunnel support work, There is no need for the operator to bolt the divided support members together. Therefore, the tunnel support can be constructed in an extremely short time, and the construction safety is greatly improved.

  Further, as another embodiment of the tunnel support according to the present invention, a separate pin insertion portion is provided on the curved outer side of the end portion of each split support, and each split support is expanded using the connecting pin as a fulcrum. In this case, the two separate pin insertion portions are aligned, and the separate connection pins are inserted into the separate pin insertion portions.

  By connecting the curved outer side with a separate connecting pin while the end surfaces of the split support are in contact with each other, the connecting strength by the connecting pin by the inner side of the bending and the connecting strength by the compressive force of the end surface by the axial force can be reduced. By adding the connection strength with a separate connection pin, the connection strength of the connection portion of the divided support can be increased.

  The present invention also extends to a tunnel support construction method, which comprises at least two curved split support works, each split support work being connected to another split support work. A pin insertion part is provided on the curved inner side of each part, the pin insertion part of each divided support work to be connected is aligned, and the tunnel support work in which the connection pin is inserted into both pin insertion parts is divided into each support part. The first step of transporting to the building place with the work closed, the second part of each split support work is expanded with the connecting pin as a fulcrum, and the end of each split support work is contacted to construct the tunnel support work It consists of steps.

  According to the construction method of the present invention, in the process of transporting to the construction site, each divided support is transported in a closed state (small size) while being connected via the connection pin, so that efficient transport work Can be realized.

  And at the tunnel support construction site, the tunnel support works can be formed by holding the tunnel support works with the gripping part of the elector device, etc., and expanding each divided support work to build the tunnel support works. it can. Therefore, it is not necessary for the worker to bolt the divided support works to each other, so that the tunnel support work can be performed in an extremely short time and efficiently. Furthermore, since the work of bolting the worker in the vicinity of the face becomes unnecessary, the construction safety is remarkably improved.

  As can be understood from the above description, according to the tunnel support work and its construction method of the present invention, the two curved split support works are connected by the connecting pin inside the curved part of their ends, At the construction site, it is possible to form a tunnel support simply by expanding the split support and bringing both end faces into contact with each other, and the tunnel support can be efficiently constructed in a short time.

It is a disassembled perspective view of Embodiment 1 of the tunnel support work of this invention. It is the perspective view which showed the state in which Embodiment 1 of the tunnel support work was formed. It is the perspective view which showed the state which Embodiment 1 of the tunnel support construction closed. It is the figure explaining the construction method of the tunnel support work of this invention, Comprising: It is the schematic diagram which showed the state which is conveying the tunnel support work of the state closed in the tunnel. It is the schematic diagram which showed the state which has expanded the tunnel support work in the construction place of a tunnel support work. It is the schematic diagram which showed the state by which the tunnel support work was constructed in the construction place of the tunnel support work. It is the perspective view which showed Embodiment 2 of the tunnel support work. It is the perspective view which showed Embodiment 3 of the tunnel support work. It is the schematic diagram explaining the calculation method which determines the specification of a connection pin.

  Hereinafter, embodiments of a tunnel support and its construction method according to the present invention will be described with reference to the drawings.

(Embodiment 1 of tunnel support work)
1 is an exploded perspective view of a first embodiment of the tunnel support according to the present invention, FIG. 2 is a perspective view showing a state in which the first embodiment of the tunnel support is formed, and FIG. 3 is a tunnel support. It is the perspective view which showed the state which Embodiment 1 of the construction closed.

  As shown in FIG. 1, the tunnel support 10 shown in FIG. 2 is composed of split support works 1 and 1 made of two H-shaped steels.

The split support 1 has a curved shape corresponding to the cross-sectional shape of the tunnel to be constructed, and the pin is inserted into the curved inner side (IN side shown in FIG. 1) of the end 1a connected to the other split support 1 A portion 3 is provided, and a steel plate 2 is welded to the end 1a to form a wide end surface.
Further, a steel leg plate 4 is welded to the end face of the leg portion of the split support 1.

  As shown in FIG. 2, the pin insertion portions 3, 3 of the two divided support members 1, 1 are aligned, and the connecting pin 5 is inserted into both the pin insertion portions 3, 3. , 1 are brought into contact with each other to form a tunnel support 10.

  FIG. 2 simulates a state in which the tunnel support 10 is installed in the tunnel, but when the tunnel support 10 is installed and becomes familiar with the tunnel wall surface, the tunnel support 10 applies the earth pressure P from the tunnel wall surface. Will receive.

  Then, when the tunnel support 10 receives the earth pressure P, an axial force N (compression force) acts in the tunnel support 10 in the axial direction.

  The two split support members 1 and 1 are connected to each other by the connecting pin 5 inside the curved portions of the end portions 1a and 1a, and the end surfaces 2 and 2 are merely in contact with each other. Since the (compressive force) is generated, the divided support works 1 and 1 are integrated, and the self-supporting tunnel support work 10 can resist the earth pressure P.

  On the other hand, when the tunnel support 10 is transported into the tunnel by a cart (not shown) or when the tunnel support 10 is transported to a construction site by a gripping portion of an unillustrated erector device, as shown in FIG. The two divided support works 1 and 1 are closed via the connecting pin 5 (X1 direction) to form a closed tunnel support work 10 '.

  Thus, by transporting as a closed tunnel support 10 ′ having a reduced overall size, the efficiency is improved in a state where the two divided support works 1 and 1 are connected without being separated by the connecting pin 5. Thus, the tunnel support 10 'can be transported. Furthermore, when the inside of the already-constructed tunnel support 10 is transported, the tunnel support 10 'can be transported to the face side without interfering with the already-constructed tunnel support 10 become.

(Embodiment of tunnel support construction method)
Next, a tunnel support construction method will be described. Here, FIG. 4 is a diagram for explaining the tunnel support construction method of the present invention, and is a schematic diagram showing a state where the tunnel support in a closed state is being transported in the tunnel, and FIG. It is the schematic diagram which showed the state which has opened the tunnel support work in the construction place of a tunnel support work. FIG. 6 is a schematic view showing a state where the tunnel support work is performed at the tunnel support work place.

  As shown in FIG. 4, in a tunnel T such as a mountain tunnel, shot concrete C is constructed on the tunnel wall surface, and on the inner surface of the shot concrete C, a tunnel support 10 is constructed at a predetermined pitch in the tunnel axis direction. ing.

  Inside the tunnel support 10 that has already been constructed, the tunnel support 10 ′ that is closed by the gripping portion of the unillustrated elector device is transported to the face K side (Y1 direction).

  Next, as shown in FIG. 5, the tunnel support 10 ′ in the closed state by operating the grip portion of the erector device is gradually expanded (in the X2 direction), and the tunnel is fully expanded as shown in FIG. 6. After the support work 10 is formed, the formed tunnel support work 10 is installed at the construction site, and the construction of the tunnel support work 10 is completed.

  According to the construction method shown in the figure, in the process of transporting to the construction site, each divided support 1, 1 is transported in a closed state (small size) while being connected via the connection pin 5, which is efficient. Can be realized.

  In addition, at the construction site of the tunnel support 10, the tunnel support 10 'that is closed by the gripping portion of the erector device is gripped, and each divided support 1 and 1 is widened to form the tunnel support 10, and promptly The tunnel supporter 10 can be built in

  Therefore, since it is not necessary for the worker to bolt the divided support works 1 and 1 to each other, the tunnel support work 10 can be constructed in an extremely short time and efficiently, and further, work can be performed near the face K. Construction safety is improved because the work of connecting the bolts by workers is not necessary.

(Embodiment 2 of tunnel support work)
FIG. 7 is a perspective view showing a second embodiment of the tunnel support work.
In the tunnel support 10A shown in FIG. 7, each of the two divided supports 1 ′ and 1 ′ includes pin insertion portions 3 and 3 on the curved inner side of the end, and the pin insertion of each of the divided supports 1 ′ and 1 ′ is performed. The portions 3 and 3 are aligned, and in addition to the connecting pin 5 being inserted into both pin insertion portions 3 and 3, each of the two split supporters 1 ′ and 1 ′ is outside the curved end ( Provided with separate pin insertion portions 3 ′ and 3 ′ on the OUT side shown in FIG. 7, both of the separate pin insertion portions 3 ′ and 3 ′ are aligned and a separate connection pin 5 ′ is inserted It is.

  By connecting the curved outer side with a separate connecting pin 5 ′ in a state where the end surfaces 2 and 2 of the divided supporters 1 ′ and 1 ′ are in contact with each other, the connection strength by the connecting pin 5 on the curved inner side and the end surface by the axial force By adding the connection strength by the separate connection pin 5 ′ outside the curve to the connection strength due to the compressive force, the connection strength of the connection portion of the divided support 10 </ b> A can be increased.

(Third embodiment of tunnel support work)
FIG. 8 is a perspective view showing a third embodiment of the tunnel support work.
In the tunnel support 10B shown in FIG. 8, each of the four split support works 1 "includes a pin insertion part 3 inside the curved portion of the end, and the pin support parts 3 and 3 of the adjacent split support works 1" and 1 ". Are aligned and the connecting pin 5 is inserted, and this connecting portion is provided in a total of three places.

  Since the tunnel supporting work 10B is composed of four divided supporting works 1 ", a large-sized tunnel supporting work 10B can be formed by expanding the four divided supporting works 1" and bringing the end faces into contact with each other. Therefore, it is suitable for supporting a tunnel having a large cross-sectional dimension.

  In addition, although illustration is omitted, as a tunnel support applied to a tunnel having a complicated cross-sectional shape, the cross-sectional shape of the tunnel can be obtained by applying a structure in which three or more divided support works are connected to each other by a connecting pin. Can be easily adapted to.

(Specification method for connecting pins)
Next, an outline of a method for determining the specification of the connection pin in the tunnel support connected by one connection pin inside the curve shown in FIGS. Here, FIG. 9 is a schematic diagram illustrating a calculation method for determining the specifications of the connecting pin.

The following equation is derived from the balance of moments around the point O shown in FIG.
SuL = M − NL / 2
M = SuL + NL / 2
Where M: Bending moment acting on the connecting part of the split support, N: Axial force acting on the connecting part of the split support, L: Length of the arm from the rotation center to the connecting pin position, Su: Connecting pin Shear strength (tensile strength / 1.3 = Nu / 1.3)

In determining the required design tensile strength Nu of the connecting pin, the acting axial force is set to zero for simplicity.
M _A = SuL = NuL / 1.3
Nu = 1.3 M _A / L = 1.3 × 23.5 / 0.18 = 169.7 kN = 169700 N
Where, M _A : 23.5kNm for the bending strength target value of the joint of the split support, Nu: Necessary bolt strength, L: 0.18m for the arm length from the rotation center to the connecting pin position

  From the unillustrated hexagon bolt minimum tensile load table (JIS B 1051 Table 6), φ20mm, strength category 8.8 203000 N> 169700, φ22mm, strength category 6.8 182000 N> 169700, φ24mm, strength category 5.6 176000 N> It becomes 169700, and connection bolts of these specifications can be applied.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and there are design changes and the like without departing from the gist of the present invention. They are also included in the present invention.

  1, 1 ', 1 "... split support, 1a ... end, 2 ... plate (end face), 3, 3' ... pin insertion part, 4 ... leg plate, 5, 5 '... connecting pin, 10, 10A, 10B ... Tunnel support, 10 '... Closed tunnel support, T ... Tunnel, K ... Face, C ... Shotcrete

Claims (3)

With at least two curved split supports,
Each split support has a pin insertion part inside the curve of the end connected to the other split support,
The pin insertion portions of each divided support work to be connected are aligned, and the connection pins are inserted into both pin insertion portions,
Tunnel support works, where the end faces of each split support work are in contact with each other when the split support work is expanded with the connecting pin as a fulcrum. A separate pin insertion part is provided on the curved outer side of the end of each divided support,
The two separate pin insertion portions are aligned when each divided support is expanded with the connection pin as a fulcrum, and the separate connection pin is inserted into both separate pin insertion portions. Tunnel support work. Provided with at least two curved split supports, each split support has a pin insertion part inside the end of the joint connected to the other split support, and pin insertion of each split support connected A first step of transporting the tunnel support in which the parts are aligned and the connecting pins are inserted into both pin insertion parts to the erection place with each divided support closed,
A tunnel support construction method comprising a second step in which each split support is expanded with the connecting pin as a fulcrum, and the end faces of each split support are brought into contact with each other.

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