JPH0756200B2 - Tunnel widening method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a method for widening a tunnel of a railway such as a commercial line.

<Problems to be Solved by the Present Invention> With the increase in traffic volume in modern society, widening of roads, enlargement or speeding up of train bodies, etc. are becoming indispensable.

Under these circumstances, tunnel widening work is inevitably performed frequently.

In the conventional tunnel widening work, the concrete of the tunnel is exfoliated over a wide area, which may cause the surrounding ground to collapse, which impairs the safety of the work.

In addition, particularly in the case of widening tunnels such as railways on business lines, it is very difficult to work efficiently and safely because it is necessary to work within a limited short time from the last train to the first train. Met.

<Purpose of the present invention> The present invention has been made to solve the above-mentioned problems, and it is possible to prevent the collapse of the ground around the tunnel and to expand the tunnel. The purpose is to provide a method.

<Structure of the Present Invention> An embodiment of the present invention will be described below with reference to the drawings.

<a> Drilling (Fig. 1) From the inner peripheral surface of the concrete 11 of the tunnel 1 for widening,
A plurality of holes 12 are drilled to the inside of the natural ground 2 located around the concrete 11 by an excavator or the like.

Since the widening range of the tunnel 1 is determined by the upside-down of the ground hole 2, the holes 12 are equally drilled at a predetermined depth.

The opening area of the hole 12 should be as large as possible, and the area where the concrete 11 should be removed later should be made small so that the concrete 11
To facilitate the removal work of.

However, when the opening area of the hole 12 is increased, surrounding earth and sand are likely to collapse, so a plate (not shown) slightly smaller than the opening area is also used when fixing the lock bolt 3 to be described later. Press 2 to reinforce.

Further, depending on the strength of the natural ground 2, if the opening area is too large, the surrounding earth and sand may be easily collapsed. Therefore, the hole 12 having a small area where the lock bolt 3 described later can be fixed is opened.

Further, the drilling interval and the number of drilling holes 12 are, as described later,
The surrounding rocks 2 by the lock bolts 3 fixed in the holes 12.
A predetermined drilling interval and the number of drilling holes that can prevent collapse of the concrete 11 and can peel off the concrete 11 are calculated by mechanical calculation, and drilling is performed over the entire inner peripheral surface of the concrete 11.

<B> Fixing of the lock bolt (Fig. 1) Insert the lock bolt 3 into each hole 12 and drive the lock bolt 3 into the ground 2.

Then, when the concrete 11 is removed, a predetermined tension force is applied to the lock bolt 3 so that the surrounding ground 2 does not collapse, and the lock plate 3 is fixed.

At this time, as described above, in order to prevent the ground 2 from collapsing, a plate or the like may be attached together.

<C> Removal of concrete (Fig. 2) After fixing the lock bolt 3 in the hole 12 if necessary,
A small fracture hole 13 is opened in the concrete 11 between the 12 areas.

Then, the arrowhead 4 or the like is inserted into the breaking hole 13 to break and remove the surrounding concrete 11.

<D> Removal of exposed ground (Fig. 3) The exposed ground 21, which is exposed by removing the concrete 11, is destroyed by the arrow 4 or the like in the same manner as the concrete 11, and removed.

Therefore, the width L is increased by the width L from the outer peripheral surface of the concrete 11 before widening to the exposed natural ground 2 by removing the exposed natural ground 21.

<E> Placing of concrete (Fig. 4) After removing all exposed ground 21, the concrete 11 is newly placed on the surface of the exposed ground 2 with the lock bolt 3 fixed, and widening work To finish.

At this time, if the concrete 11 is sprayed thinly on the surface of the natural ground 2 before placing the concrete 11,
Can be reinforced more reliably.

<Effects of the Present Invention> Since the present invention has been described above, the following effects can be expected.

That is, conventionally, when the tunnel widening work is performed, the concrete is exfoliated over a wide area, which may cause the surrounding ground to collapse, and the work safety is impaired.

Also, especially in the case of widening construction of tunnels such as railways on business lines, it is necessary to work within a limited short time from the last train to the first train, so it is very difficult to work efficiently and safely. Met.

Therefore, the present invention, after fixing the rock bolts in the ground around the concrete, remove the concrete and the ground of a predetermined widening range, and place a new concrete, safe and reliable, quickly widening work I was able to do it.

Therefore, it became possible to prevent the rocks around the tunnel from collapsing with rock bolts and to expand the tunnel.

Therefore, even in the case of widening a tunnel such as a railroad on a commercial line, the widening of the tunnel can be performed safely, reliably and promptly.

[Brief description of drawings]

Fig. 1: Explanatory diagram of concrete and ground holes drilled and lock bolts fixed Fig. 2: Explanatory diagram of concrete breaking between holes with arrowhead Fig. 3: Exposed space between holes Illustration of the state where the ground is removed Fig. 4: Illustration of the state where new concrete is placed on the exposed ground

Claims (1)

[Claims] 1. A plurality of holes are drilled from the inner peripheral surface of the concrete of the tunnel to the inside of the ground, and lock bolts are inserted into the holes to settle in the ground, and the concrete and the protrusion between the holes. The widening method of the tunnel, characterized by removing the existing ground and placing new concrete on the exposed ground.