KR20030037086A - A Shallow Semi Cut and Cover Tunneling Method in Soft Ground and at Portal - Google Patents

Abstract

PURPOSE: A shallow semi cut and cover tunneling method is provided to reduce the cut amount of the ground, to reduce the cutting time and to quickly plant trees the cut portion. CONSTITUTION: The ground at portal of a tunnel is cut in an arch shape. A pair of underground continuous walls(2,4) is buried in the arch-shaped ground at an interval corresponding to the width of the tunnel. A concrete arch structure(6) is combined with the upper part of the underground continuous walls. Earth and sand are covered on the concrete arch structure. Earth and sand inside the underground continuous walls and the concrete arch structure are excavated. A concrete for finishing is lined inside the underground continuous walls and the concrete arch structure. Then the tunnel is excavated. Thereby, the cut amount of earth and sand and the cutting time is reduced. The cut portion and the covered portion are planted trees quickly and the earth and the sane are stored and managed more easily.

Description

A Shallow Semi Cut and Cover Tunneling Method in Soft Ground and at Portal}

The present invention relates to a semi-adhesive tunnel construction method, and more particularly, to a construction method for constructing a tunnel in a soft ground condition with a thin tunnel shaft or toffee.

In particular, the above-mentioned mountain tunnel should be able to minimize the destruction of the ecosystem environment while the tunnel entrance matches the surrounding landscape, so the greening of the cut surface should be considered from the early stage of construction.

On the other hand, as part of the above-mentioned efforts, the New Austrian Tunneling Method (NATM) has been researched and developed. This tunnel construction method is the first tunnel construction method performed by Rabcewicz of Austria, and the rock foundation itself, which forms the surface of mountainous areas. It is an excavation method with excellent workability, which is fixed with rock bolts using the supporting force and then reinforced with shotcrete and support material to stabilize the ground and continue tunnel excavation.

In Korea, the excavation method as described above has been utilized since the construction of the subway in the 1980s, and is mainly used for difficult construction of mountain tunnels, such as drilling and blasting, bagging, shotcrete casting, rockbolt installation, and steel groundwork installation. Through the excavation process.

In other words, the NATM method allows the ground itself to play a role as a common treasure by reinforcing the ground at the proper wall displacement state with the minimum allowable displacement occurring inside the tunnel due to the ground stress that is opened due to the excavation during tunnel excavation. In the construction method, the support material is provided to allow the ground and the support material to be balanced in a state where the displacement is allowed to some extent but the strength of the land is not lost.

In addition, until now, mountain tunnels have first formed shafts and penetrated the tunnels, and then, a large portion of the openings were formed in an arch shape like a tunnel, and then the soil was filled again and the surroundings of the shafts were restored to their original shape. After forming a steep slope at the shaft position of the main tunnel, connect the steep slope to construct an open tunnel with an arch structure, fill the soil around and around the cut tunnel, plant the vegetation, and landscaping the landscape. It has been built by excavating a tunnel.

That is, as shown in Figures 1a and 1b, excavated to the shaft portion and the soil was excavated, and then after the reinforced surface of the shaft with a rock bolt (a) and steel fiber reinforced shotcrete (b) multi-stage grouting around the shaft Reinforcement is installed, and the temporary door (d) is installed next to the temporary support (c).

Next, the sandbags (e) are installed above and to the left and right of the shaft door (d) to protect the shaft door (d), blast through the inside of the tunnel, and then install shotcrete and waterproofing and drainage, lining concrete After completion of the interior of the main tunnel by pouring, the steel gate (d) is demolished, the arched reinforced concrete structure (f) is constructed at the opening part, and the soil is filled up and surrounding the structure (f) to restore the excavation site. Plant herds and trees.

However, in the tunnel construction method as described above, not only the continuous management to maintain the integrity of the shaft surface for a long period of time, but also the problem of the need to open a separate landfill because it is difficult to reuse the soil for covering the soil. there was.

As a method for solving such a problem, a construction method such as Korean Patent Application Publication No. 2001-0064207 has been proposed in Korean Laid-Open Patent Publication, and the disclosed content is a shaft position of the main tunnel in constructing a mountain tunnel in which an opening section tunnel is planned. After forming a steep slope on the ground, connect the steep slope to construct an open tunnel with an arch structure. It is about.

That is, in the construction method disclosed in Japanese Patent Application Laid-Open No. 2001-0064207, as shown in FIG. 2, the first excavation of the shaft portion 101 leading to the entrance of the bonn tunnel at the time of the tunnel according to the conventional tunnel construction method is carried out. The shaft portion 101 revealed by the steep slopes 102 is formed, and the cut tunnel is constructed by the reinforced concrete arched structure 103.

The arcuate structure 103 is constructed as a structure that can support earth pressure and load as a linear shape such as the inside of the concrete lining, and the soil layer 104 is filled on the arched structure 103 to be filled.

The earth and sand as backfill fill material for the shaft portion 101 is excavated and used in the earthen ground, and the arch structure 103 is turned into a shaft while performing landscaping work on the soil layer 104 formed as described above. It continues to be drilled to penetrate the main tunnel 105, and the concrete lining 106 is placed therein to complete the tunnel.

Unexplained reference numeral '107' denotes the base plate, and '108' denotes the cut surface of the base plate and the interface with the cover.

Completion and landscaping of the arched structure 103 from the excavation of the shaft portion 101 is made much faster than the previous method, even if the completion period to the main tunnel 105 takes a long time, There is no need for continuous management to keep the shaft surface intact, as well as it is possible to immediately reuse the earth and sand generated during the excavation of the shaft portion 101 when covering the soil. Will disappear.

However, the conventional tunnel construction method as described above is to cut too much amount, accordingly, it takes a long period of cutting work, it is difficult to store and manage a large amount of cut powder for the cover, If the powder is lost in nature, there is a disadvantage that it can damage the surrounding environment.

In addition, since the cut surface must be maintained as a steep slope, there is a problem that the risk of collapse of the cut surface remains, and the maintenance of the cut slope is difficult and expensive.

The present invention has been made to solve the above-mentioned disadvantages and problems, the object of the present invention can significantly reduce the amount of cut, thereby shortening the cut operation period, as well as the cut portion The purpose of this study is to provide a semi-adhesive tunnel construction method in the soft ground condition where the tunnel shaft or the toffee can be prematurely recorded.

This reduces the amount of cut powder stored and managed, making it easier to store and manage the cut powder, as well as reducing the risk of natural loss of cut powder and damage to the surrounding environment due to the cut powder loss. The present invention aims to provide a semi-adhesive tunnel construction method in the soft ground condition where the tunnel shaft or the toffee are thin.

In addition, the present invention has a structure in which the cut surface is not maintained as a steep slope, which can eliminate the risk of collapse of the cut surface at the same time, and accordingly, the tunnel shaft is easy to maintain the cut slope and requires less cost. The purpose of this study is to provide a semi-adhesive tunnel construction method in soft ground condition with thin section or toffee.

1a and 1b is a view for showing the shaft portion of the tunnel constructed by a general tunnel construction method,

Figure 2 is a cross-sectional view for showing a shaft structure of a conventional tunnel,

3A to 3F are schematic views for showing a process for the tunnel construction method according to the present invention.

In order to achieve the above object, the present invention, in the completion of the bone tunnel by applying NATM consisting of excavation process, such as drilling and blasting, rubbing treatment, shotcrete installation, rockbolt installation, steel support construction, the shaft of the bone tunnel Cut the ground into a certain section of arcuate surface at a location, and form a pair of underground continuous walls in a buried form at a position having an interval corresponding to the width of the bone tunnel on the ground of the formed arcuate surface, and the pair of underground Bonding the concrete arch structure to the upper side of the continuous wall, covering the soil generated by the cutting operation to the upper side of the concrete arch structure, and excavating the earth and sand existing inside the pair of underground continuous walls and the concrete arch structure, After lining the pair of underground continuous walls and the inner surface of the concrete arch structure with finishing concrete, the main tunnel is excavated. Provides a semi-adhesive tunnel construction method in soft ground condition with thin tunnel shaft or toffee.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

One embodiment of the present invention relates to a configuration of a tunnel to which NATM is applied, as shown in FIGS. 3A and 3F.

As described above, the NATM method is a method that can reinforce the ground in an appropriate wall displacement state immediately after excavation with a minimum allowable displacement occurring inside the tunnel due to the ground stress that is opened due to the excavation during tunnel excavation. It is described in the description of the detailed description thereof will be omitted.

On the other hand, the shaft structure of the tunnel according to the present invention is composed of a pair of underground continuous walls (2) and (4), a concrete arch structure (6), a cover layer (8), and a finishing concrete lining layer (10). .

That is, the pair of underground continuous walls (2) (4) is formed on the ground (12) of the bone tunnel shaft position arcuate surface formed according to the cutting work at a space corresponding to the width of the bone tunnel (14). It is provided in the form embedded in the ground (16).

In addition, both ends 20 and 22 of the concrete arch structure 6 provided above the pair of underground continuous walls 2 and 4 as described above have an upper end 24 of the concrete arch structure 6. And (26), respectively, and the soil layer generated and stored according to the cutting operation is filled back to the upper side of the concrete arch structure 6 so that the cover layer 8 is formed.

In addition, the pair of finishing concrete lining layer 10, the pair of underground continuous walls (2) (4) and the excavated soil (28) present in the concrete arch structure (6) after the pair It is formed by installing on the inner and bottom surfaces of the continuous wall (2) (4) and the concrete arch structure (6).

In addition, the structure as described above, is constructed to be able to excavate the tunnel in a mountainous area, or an urban area according to the method according to the present invention, the construction method of the shaft portion of the tunnel is cut (S10), underground continuous wall ( It is composed of a number of processes such as landfill (S20) of 2) (4), coupling (S30) of the concrete arch structure (6), cover (S40), excavation (S50), lining (S60).

That is, the ground is cut into the arched surface at a predetermined section at the shaft position of the bone tunnel, and a pair of underground grounds are disposed at the spaces corresponding to the width of the bone tunnel on the left and right grounds of the arched surface formed by the cutting work. The continuous wall (2) (4) is to be formed in the form of embedding in the ground.

In addition, after joining the both ends of the concrete arch structure (6) separately formed above the pair of underground continuous walls (2) and (4) formed by the work process as described above generated by the cutting operation The soil is covered with the concrete arch structure (6).

Further, after excavating the earth and sand existing inside the pair of underground continuous wall (2) (4) and concrete arch structure (6), the pair of underground continuous wall (2) (4) and concrete arch structure ( 6) Lining the inner surface with finishing concrete, and then the main tunnel will be excavated.

As described above, the semi-adhesive tunnel construction method in the soft ground condition of the tunnel shaft portion or toffee thin,

First, the amount of cut can be greatly reduced,

Secondly, the cutting period can be shortened according to the reduction of cutting amount.

Third, the cut and cover parts can be recorded early according to the shortening of the cutting work period.

Fourth, it is easy to store and manage the cut soil sediment according to the cut amount of cut,

Fifth, because it is easy to store and manage the cut soil, it is possible to reduce or exclude the risk of natural loss of the cut powder and the damage of the surrounding environment due to the loss of the cut powder,

Sixth, because the cut surface is not maintained as a steep slope, the risk of collapse of the cut surface can be ruled out.

Seventh, according to the original exclusion of the risk of collapse of the cut surface, there is an advantage such that the maintenance of the cut slope is easy and the cost is reduced as much.

Claims (1)

In the completion of this tunnel by applying NATM, which consists of excavation processes such as drilling and blasting, buffing, shotcrete casting, rockbolt installation and steel support construction, In the shaft position of the bone tunnel, the ground is cut into a certain section of arched surface, A pair of underground continuous walls (2) and (4) are formed in the form of a buried shape on the ground of the formed arched surface at intervals corresponding to the width of the bone tunnel, Combining the concrete arch structure (6) above the pair of underground continuous walls (2) (4), and cover the soil generated by the cutting operation to the upper side of the concrete arch structure (6), Excavate the earth and sand existing inside the pair of underground continuous wall (2) (4) and concrete arch structure (6), Semi-adhesive tunnels in soft ground conditions with thin tunnels or toffee tunnels for lining the main tunnel after lining the finishing concrete on the inner surface of the pair of underground continuous walls (2) (4) and concrete arch structures (6) Construction method.