JPH066878B2 - Tunnel or underground cavity lining structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an underground storage space, an underground cavern such as an underground power plant,
The present invention relates to a lining structure for tunnels or underground cavities for primary lining or permanent lining used in tunnels and other underground excavations.

[Conventional technology]

In recent years, NATM (New Austri
an Tunneling Method) is attracting attention. NATM is based on the idea that the conventional tunnel method supports the loosening load after excavation by the steel support and the supporting force of the sheet pile.
Is a method of constructing a tunnel structure that is integrated with the ground, based on the idea of effectively utilizing the strength of the ground and maintaining the stability of the tunnel. Since the construction management is carried out by on-site measurement and the ground behavior is monitored, it is a construction method with excellent safety and economy that enables design and construction suitable for the ground condition.

This will be explained with reference to FIG. 5 and FIG. ,
..., then the steel support 32 is installed, the tie rod (steel rod) 33 is installed between the steel support 32 installed last time, and the secondary sprayed concrete 34 is finally installed. The lining is done. Also, the lock bolt may be done after the completion of secondary shotcrete.

[Problems to be solved by the invention]

In the conventional NATM, immediately after excavation, the primary lining is constructed by properly using the supporting materials such as the primary sprayed concrete 30, the lock bolts 31, and the steel supporters 32, and finally the secondary sprayed concrete 34 is constructed. However, since the sprayed concrete 30, 34 is constructed with a considerable thickness, the consumption of the relatively expensive sprayed concrete increases and the cost rises, and the sprayed concrete 30, 34 and the steel support 32 Since the strength of the connecting surface is weak, the transmission of force in the tunnel excavation direction is insufficient, and there is a problem that it is weak against concentrated loads and partial ground subsidence. Further, since the natural stress is concentrated on the rock bolt driving portion, there is a problem that it causes damage.

The present invention is to solve the above problems, and it is an object of the present invention to provide a lining structure for a tunnel or an underground cavity that can reduce the consumption of shotcrete and lessen the strength of the ground. And

[Means for solving problems]

Therefore, the lining structure of the tunnel or the underground cavity of the present invention is a lining structure for lining the excavated surface of the tunnel or the underground cavity or the surface formed with sprayed concrete on the excavated surface, and is a polygon formed by sprayed concrete. It is characterized in that it is provided with a shaped lattice structure and a lock bolt that is driven from the node of the lattice structure to the ground. The lattice structure may be formed by reinforcing bars or steel frame supports and shotcrete.

[Action]

In the present invention, for example, as shown in FIG. 1 and FIG. 2, the primary sprayed concrete 1 is applied to the excavated portion,
After that, the reinforcing bar supports 2 are assembled along the inner surface of the primary sprayed concrete 1 so as to form a triangular lattice, and the sprayed concrete 4 is applied to the lattice portion so as to obtain a predetermined cross-sectional shape and cross-sectional area. Lattice structure 5
After the lining is formed and the lining is completed, the lock bolt 6 is driven at each node of the lattice structure.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing an embodiment of a lining structure for a tunnel or an underground cavity of the present invention, and FIG. 2 is a perspective view showing a main part thereof.

The examples shown in FIGS. 1 and 2 show a lining structure when the ground after excavation is not very self-sustaining, and the tunnel face is blasted or excavated for one span length by a machine such as a road header. After that, the primary shotcrete 1 is applied to the excavated portion, the temporary shotcrete 1 is used to secure the temporary stability of the ground, and then the reinforcement bar support 2 is formed along the inner surface of the primary shotcrete 1 with a triangular lattice. Assemble to form. At that time, the joint with the lining structure 3 which has already been constructed is a bolt joint or a reinforcing bar lap joint, and after the reinforcing bar support 2 is assembled, the sprayed concrete 4 is applied to the lattice part so as to obtain a predetermined sectional shape and sectional area. Then, the lattice structure 5 made of reinforced concrete is formed, and after the lining is completed, the lock bolt 6 is driven at the node of the lattice structure.

In the above embodiment, the reinforcing bar support 2 is used to form the lattice structure 5. However, a steel frame supporting bar made of shaped steel may be used, and the reinforcing bar or the steel frame supporting bar 2 may be used.
Instead of using, the lattice structure may be directly constructed by spraying concrete with fibers or spraying concrete with wire mesh.

In addition, when the ground after excavation is self-supporting, the grid structure 5 is immediately constructed without constructing the primary shotcrete 1 and the ground surface between the grid structures 5 is prevented from being separated from the ground. It is sufficient to use shotcrete that is thinner than the lattice part.

Next, another embodiment of the lining structure according to the present invention will be described with reference to FIGS. 3 and 4. In FIG. 3, a reinforced rectangular support grid is formed along the inner surface of the primary shotcrete 21. In this example, the reinforced concrete lattice structure 20 is assembled, and after the lining is completed, the lock bolts 19 are placed at the nodes of the lattice structure. The lattice structure is not limited to this and may be any polygonal structure. FIG. 4 shows that a spacer 23 such as Styrofoam is fixed to the recess formed by the lattice structure 20 including the primary sprayed concrete 21 and the reinforcing bar support 22, and the decorative sprayed concrete 24 is applied on the spacer 23 to complete the lining. An example is shown.

〔The invention's effect〕

As described above, according to the present invention, by adopting the lattice structure as the lining structure, the consumption amount of sprayed concrete can be saved as compared with the conventional NATM lining structure, and the lining structure has the lattice structure. Because of this, the continuity of the lining structure does not deteriorate in the tunnel excavation direction, and concentrated loads and partial ground subsidence can be prevented.

Further, since the rock bolt is driven at each node of the lattice structure, it is possible to disperse the natural stress concentrated on the rock bolt driving portion.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an embodiment of a lining structure of a tunnel or an underground cavity of the present invention, FIG. 2 is a perspective view showing its lattice structure, and FIG. FIG. 6 is a perspective view showing another embodiment of the tunnel or underground lining structure, FIG. 4 is a perspective view showing its lattice structure, FIG. 5 is a perspective view showing a conventional underground lining structure, and FIG. FIG. 3 is a perspective view showing the main part thereof. 1, 21 ... Primary sprayed concrete, 2, 22 ... Reinforcing bar support, 3 ... Lining structure, 4 ... Sprayed concrete, 5, 20 ...
Lattice structure, 6, 19 ... Rock bolt.

Claims (3)

[Claims] 1. A lining structure for lining an excavated surface of a tunnel or an underground cavity or a surface having sprayed concrete formed on the excavated surface, the polygonal lattice structure formed by sprayed concrete, and the lattice structure of the lattice structure. A lining structure for a tunnel or an underground cavity, which comprises a rock bolt driven from a node to the ground. 2. The lining structure for a tunnel or an underground cavity according to claim 1, wherein the sprayed concrete forming the lattice structure contains fibers or wire mesh. 3. A lining structure for lining an excavated surface of a tunnel or an underground cavity or a surface formed with sprayed concrete on the excavated surface, which is a polygonal lattice formed by reinforcing bars or steel frame supports and sprayed concrete. A lining structure for a tunnel or an underground cavity, comprising a structure and a rock bolt placed in the ground from a node of the lattice structure.