JPH083516Y2 - Basic element for tunnel construction - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a tunnel lining element that is buried in a substantially gate shape when, for example, a tunnel crossing over a railway or a road is constructed. , The foundation element buried in the bottom.

[Prior Art] As a method of constructing a tunnel that crosses under a railway or road, instead of the conventional construction method in which the lining body is not divided by the cast-in-place concrete, the sectional shape is rectangular and After the long concrete or steel tunnel lining element of is propelled to the ground and buried in a gate shape, after mutually connecting the elements to each other,
A method of excavating and removing earth and sand inside an element connecting body is known.

Among the elements buried in the gate shape, the foundation element buried in the lowermost part has a means for supporting a large load, for example, by arranging two or more elements side by side and interconnecting them to expand the foundation surface. .

[Problems to be solved by the invention] However, in order to connect the basic elements arranged side by side, a method is used in which the bolts are connected by reinforcing bars and then concrete is placed to solidify them. Is not enough connection strength,
At present, the development of more effective basic elements is desired.

[Means for Solving the Problems] The present invention is a basic element made to solve the above problems, wherein a side part is closed by a steel plate, and at least a longitudinal direction and a hollow shape that opens downwards, In addition, it is characterized in that a truss or lattice-shaped reinforcing material is assembled inside it, and further, at the tip in the propulsion direction, the projections that form the front and rear steps are dividedly formed, and concrete is poured inside the hollow. There is.

[Operation] According to the tunnel construction foundation element of the present invention, the concrete cast inside adheres to the ground and the whole is integrated with the ground, so that sufficient strength is obtained as a foundation and there is no risk of subsidence. Also, when propelling, even if the face has a large cross section, the projecting part is formed at the tip and the step is provided, so the stress (pressure) of the ground is not concentrated at one point at the tip and is dispersed. , Acts as a strong resistance to the collapse of the face. Furthermore, the hollow interior can be utilized as an effective work space for the entry and exit of workers, the supply of excavation power during propulsion, the arrangement of conveyors, and the like.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a tunnel constructed in the ground using the foundation element according to the present invention.

This tunnel 1 is a gate type composed of a vertical portion 1A and a horizontal portion 1B connecting them by horizontally propelling a plurality of elongated hollow steel elements 2 orthogonal to the lining cross section with respect to the ground G. PC cables 3 are inserted into the holes provided in each element 2 and arranged at regular intervals in the longitudinal direction, and both ends thereof are fixed to the upper part of the base element 4.

Next, concrete 5 is filled and placed inside each element 4 and the joint space except the base element 4.

When the concrete 5 reaches the required strength, both ends of the PC cable 3 are tensioned in the base end element 4 and prestress is introduced into the concrete 5 to fix it, and then the concrete is filled and placed in the foundation element 4. Then, it is constructed by excavating and removing the earth and sand inside the element connecting body 6.

FIG. 2 shows another example of a tunnel constructed in the ground G using the foundation element 4.

This tunnel 7 shows an example in which a concrete element 8 is used instead of the steel element 2 used in the tunnel 1 shown in FIG.
And a horizontal part 7B form a gate shape.

The tunnel 7 is different from the steel element 2 in that the concrete element 8 is not hollow and cannot be propelled by loading an excavator inside the element 8.
A hollow steel element is propelled and then replaced by being extruded with a concrete element 8.

The PC cable 3 similar to the above is bent around the element connecting body 9 along a portion where a pulling force acts against the surrounding earth pressure.

As shown in FIG. 3, the steel base element 4 in each of the tunnels 1 and 7 has a convex cross-section, a truss reinforcing material 10 is arranged on the upper surface, both sides are covered with steel plates 11, and the inside is an upper part. A reinforcing frame 12 is appropriately incorporated to support the shaft and withstand the propulsive force, and has a hollow shape opened in the longitudinal direction and the downward direction.

In addition, the lower part is the rebar 13 necessary for the bottom of the foundation in advance.
, Or the reinforcing bars 13 are brought in and assembled before filling and placing concrete.

Further, as shown in FIG. 3, at the tip end in the propulsion direction, a projecting portion 14 projecting forward is defined and provided with a step portion 15 which is displaced forward and backward.

In promoting the foundation element 4, the face is manually excavated and the earth and sand excavated by the belt conveyor is sent backward. This facilitates the removal of various buried obstacles. The truss reinforcement member 10 on the upper surface may be a reinforcement member having a lattice structure.

Now, according to the basic element 4 of the present invention,
Since the lower part is open, the concrete placed inside adheres to the ground G, and the steel plate 11 and the truss reinforcement material
10, that is, the foundation element 4 as a whole is integrated with the ground G to obtain sufficient strength as a foundation, and there is no fear of sinking. Note that, if necessary, it is possible to lay and add scattered stones to prevent further sinking.

Further, when the basic element 4 is propelled, even if the cutting face has a large cross section, the projection 114 is partitioned and formed at the tip to provide the step portion 15, so that the stress (pressure) of the ground G is applied to the tip. It is not concentrated in one place but dispersed and acts as a strong resistance against the collapse of the face, so the propulsion work is safe.

Further, the hollow inside of the portion rearward from the tip can be widely used for the entry and exit of workers, the supply of excavation power for propulsion, the arrangement of belt conveyors, and the like. In addition to this, since the upper part is also connected by the truss reinforcement material 10, the element 2 of the wall part is continuously filled when filling the concrete.
(8) can be installed and connected, and at the same time, during propulsion, effective use such as lighting, ventilation, and entrance / exit of workers is possible.

[Effects of the Invention] As described above, according to the tunnel construction foundation element of the present invention, the side portion is closed by the steel plate, and at least the longitudinal direction and the downwardly opened hollow shape are formed, and A truss or a lattice-shaped reinforcing material is assembled, and further, at the tip in the propulsion direction, projections that form front and rear step portions are formed separately, and concrete is poured into the hollow interior, The concrete placed inside adheres to the ground, and the whole is integrated with the ground to provide sufficient strength as a foundation and there is no risk of subsidence.
Also, when propelling, even if the face has a large cross section,
Due to the stepped portion of the tip, the stress (pressure) of the ground is dispersed without concentrating in one place at the tip, it acts as a strong resistance force against the collapse of the face, and the propulsion work can be done safely.
Various effects can be obtained such that it can be used as an effective work space such as the entry and exit of workers, the supply of excavation power for propulsion, the arrangement of conveyors, and the like.

[Brief description of drawings]

FIG. 1 and FIG. 2 are front views of a tunnel constructed by using the foundation element of one embodiment of the present invention, and FIG. 3 is a perspective view of the foundation element. 1, 7 ... Tunnel, 1A, 7A ... Vertical part, 1B, 7B horizontal part, 2 ... Steel element, 4 ... Foundation element, 6, 9 ... Element connection body, 11 ... Steel plate, 10 ... …
Truss reinforcing material, 14 ... projection, 15 ... step, G ... ground.

Claims (1)

[Scope of utility model registration request] 1. A substantially gate-shaped elongated element, which is composed of vertical portions on both sides and horizontal portions connecting these vertical portions, is provided along the longitudinal direction of the ground on which a tunnel is to be constructed so as to be orthogonal to the lining cross section. It is a basic element that is buried at the bottom of the vertical part when the tunnel is constructed by excavating and removing the earth and sand inside the element connecting body while propelling and burying the elements and connecting these elements to each other. The part is closed by a steel plate and is hollow so as to open at least in the longitudinal direction and downward, and a truss or lattice-like reinforcing material is assembled inside the part. A basic element for tunnel construction, characterized in that the projecting portion to be formed is dividedly formed, and concrete is placed inside the hollow portion.