KR20000003270A - Tunnel construction method at area of thin soil surface - Google Patents

Abstract

PURPOSE: A tunnel construction method at the area of thin soil surface is provided to reduce the destruction of nature by minimizing the area cut by cutting only the necessary part of the ground. CONSTITUTION: A tunnel construction method at the area of thin soil surface comprises the steps of: sticking a H-beam(10) at left and right sides of a tunnel construction point at a regular interval; cutting the ground as ensuring a working space(40) to an appropriate depth while inserting bracing plates(30) for preventing soil collapse at the rear face of the H-beam; establishing the connecting beams(50) lengthwise to be supported by the H-beams(10) in a specific depth inside of the secured working space(40); installing a flexible mold(100) on the surface of a curved base ground and a packing body; forming a semi circle-shaped lining concrete(100) by pouring the concrete; removing of excavated soil of the inner base ground(20) and the packing body after hardening the lining concrete(100); releasing the inner and outer molding plates(70)(90).

Description

Tunnel construction method in shallow toffee area

The present invention is a tunnel construction method that is constructed in shallow toffee areas such as tunnel entry and exit, and in particular, while stabilizing slopes, it greatly reduces the amount of earthwork due to the construction of tunnels, and preserves the natural environment as much as possible without damaging it. In addition, the present invention relates to a tunnel construction method in a shallow toffee area in which a tunnel can be constructed using the ground inside the tunnel.

In general, the selection criteria for the tunnel excavation method are the construction method considering the safety, structural stability review, construction method suitable for geological condition, construction period, working environment, enviroment of surrounding facilities, and economic feasibility. Done.

However, tunnel excavation methods are roughly classified into excavation methods using explosive blasting or excavation methods using mechanical excavation equipment such as TBM. Through such a method, tunnels are gradually constructed by increasing the depth of tunnels. .

In general, in order to excavate a tunnel, the toffee layer on the upper part of the tunnel must be thicker than a certain thickness so that the tunnel can be constructed without collapsing by arching. As shown in FIG. 1, the entrance and exit of the tunnel (A) and the valley (B) are shown. ), The toffee has a shallow topographic condition, and it is inevitable that a tunnel (T) must be constructed even in a section where the toffee is shallow due to the topographical condition.

Therefore, since the ground itself is not strong in the shallow toffee can not be arching action in this case, as a conventional tunnel construction method was forced to build a tunnel in the open cut method as shown in FIG.

That is, the tunnel construction method of the conventional toffee shallow region is an open-cut method, as shown in Figure 2, excavating the ground (1) to a sufficient size for the front end lining concrete (3) of the tunnel can be built However, after cutting to a large extent so as to have a safe inclination so that the left and right slopes (2) do not collapse, the concrete inside the formwork through a copper bar process to install a formwork and a support (not shown) for forming the lining concrete After constructing the lining concrete (3), and after the lining concrete is cured, the support and formwork are dismantled, and then take the method of building the tunnel by backfilling the soil (4) on top of the lining concrete (3) There was no choice but to.

In the conventional tunnel construction method, in order to construct a tunnel at the entrance or valley of a tunnel having a toffee topographical condition, it is necessary to consider the safety of the slope and secure the required working space until the required space is secured. Accompanied by earthwork will inevitably follow.

That is, in the entrance and the valley of the tunnel, as shown by the dotted line in Fig. 1, the cutting work that almost needs to be cut down the mountain slope is made in a large range, so that the slope is formed rapidly, and the height of the slope is increased. Not only is it difficult to carry out the work, but especially after construction, the stable balance of the existing slopes is broken, causing the risk of landslides, which is the biggest problem of being a safety vulnerability.

As such, a wide range of cutting is made until sufficient space is secured to secure the safety of the tunnel construction work while the ground of the tunnel entrance / valley area is stabilized, thus destroying the stability of the ground. Rather, the steep slope is formed so that the peripheral slope of the shaft portion becomes unstable, and the height of the soil slope is formed to be relatively high, resulting in an increase in earth pressure acting on the peripheral slope of the shaft portion.

At this time, if the earth pressure (P _A ) acting on the peripheral surface of the shaft can be expressed by the formula P _A = 1 / 2γH ² K _A , where P _A is the main earth pressure, γ is the unit weight of the soil, H is the retaining wall The height, K _A, is the main dynamic pressure coefficient.

Therefore, the earth pressure P _A acting on the peripheral slope of the shaft portion is proportional to the square of the height of the soil slope H, so the soil pressure increases as the height of the soil slope increases, so that the risk of collapse of the slope increases.

In addition, large-scale cuts are made to secure sufficient working spaces, and the slopes of the large cuts are generated, which requires a lot of construction costs, prolongs the construction, destroys the natural environment, and not only looks aesthetically bad. The cost is enormous, and as the slope is made larger, the position of the shaft is formed relatively deep, and artificial valleys are formed, resulting in poor ventilation, and shading occurs in front of the shaft. There are problems.

In addition, even in the construction surface for the construction of the tunnel cross-section, such as the construction of the complex work, but the process for forming the upper cross-section can not be simplified, there is still a problem in the construction is that the air is longer.

In conclusion, in order to construct the tunnel structure by the conventional open cut method, it is necessary to excavate the soil to the extent that it does not interfere with the work, thereby breaking the stability of the slope, and also entails a lot of construction costs Many problems are inevitably followed, such as being uneconomical and taking longer to work.

Therefore, the purpose of the present invention is to shorten the construction period by drastically reducing the amount of earth excavation and refilling the soil, and to provide a tunnel construction method in a shallow toffee area that can stabilize the slope and protect nature.

Another object of the present invention is to provide a tunnel construction method in a shallow toffee area that increases workability and safety by not using a support for supporting formwork for constructing lining concrete.

Another object of the present invention is to provide a tunnel construction method in a shallow toffee area that reduces the destruction of the natural environment by cutting only necessary parts and reducing the cut area to a minimum.

1 is a view showing the topographical conditions of the section in which the tunnel is installed

Figure 2 is a cross-sectional view of the tunnel construction according to the conventional detachable method

3a to 3f are cross-sectional views of the tunnel construction of the present invention,

Figure 3a is a cross-sectional view of a state in which the earth plate is installed by driving the H-pegments on the left and right side walls of the cross section where the tunnel is installed, and in the form of an upper cross section of the tunnel.

Figure 3b is a cross-sectional view of the filling state in the working space in the same form as the upper end of the tunnel after installing the connecting beam between the H-piles

Figure 3c is a view of the state after pouring the formwork to the upper surface of the ground and the filling body poured concrete

Figure 3d is a state of removing the filling and removing the formwork by excavating the internal ground after concrete molding

Figure 3e is a view of the styropol and soil filling the upper portion of the tunnel upper lining concrete

Figure 3f is a view of the state in which the secondary lining concrete in the tunnel

4 is a perspective view of a state in which the upper section of the tunnel of the present invention is constructed;

Figure 5 is a cross-sectional view of the state in which the concrete is poured in the corner of the upper section of the tunnel of the present invention

Figure 6 is a cross-sectional view of the ready-made concrete panel is installed on the lower cross section of the tunnel of the present invention

Figure 7a is a plan view of the earth plate is installed on the back of the H-pile, the connecting beam is installed between the H-pile

Figure 7b is a side view of the earth plate installed

<Description of the symbols for the main parts of the drawings>

10: H-peg 11: T-shaped support plate 20: Base ground plate

30: earth plate 40: working space 50: connecting beam

60: Filler 70: Internal formwork 80: Space

90: Outer formwork 91: Support 100: Lining concrete

a: Polyester styropole b: Soil c: Ready-made concrete panel

Hereinafter, the technical configuration of the present invention will be described.

In the tunnel construction method of the toffee shallow region of the present invention, the H-pegments 10 are driven at regular intervals on the left and right sides of the tunnel construction point, and the semi-circular base ground 20 is formed between the inner sides of the H-pegments 10. Cut to be curved to form a), while cutting the earth 40 while securing the work space 40 to an appropriate depth while sandwiching the earth plate for preventing soil disintegration on the back of the H-pile, the secured work space 40 After installing the connecting beams 50 in the longitudinal direction so as to support the H-peg 10 at a predetermined depth therein, the work space is filled with the filling body 60 to form the outer circumferential surface of the tunnel, and the curved base ground and After installing the formwork with good flexibility on the surface of the filling body, the concrete is poured to form a semi-circular arch type lining concrete 100, and after the lining concrete 100 is hardened, the excavation and filling of the internal ground 20 Remove the sieve (60) and inside and outside It is characterized in that the tunnel is built by demolding the second formwork plate (70, 90).

That is, the present invention is to install the ground concrete in the tunnel upper section, while preventing the ground collapse of the left and right by inserting the earth plate in the H-peg perpendicular to the left and right sides of the tunnel to be built in a shallow toffee As a method of constructing the lower cross section later, the tunnel has the characteristics of the upper cross section pre-construction lower cross section post-construction.

In addition, it has the feature of using the base ground to support the formwork in order to construct the upper cross-section.

Therefore, the present invention is to stabilize the slope by inserting the earth plate in the H-piles to prevent the collapse of the soil, and also drastically reduced the amount of earth cut by digging and refilling the soil to reduce the area of the natural environment Destruction can also be reduced, and since the base ground 20 is used to support the formwork, there is no need for a copper bar process such as a support for concrete placing.

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

As an embodiment of the present invention, as shown in Figures 3a to 3f, the H-pegments 10 are driven at regular intervals on the left and right sides of the tunnel construction point, and the ground between the inner sides of the H-peg 10 is semicircular. Cut the surface to be curved to form the base ground 20, the work space 40 to the appropriate depth while sandwiching the earth-to-earth decay earth plate 30 between the H-peg 10 on the back of the H-peg 10 in the longitudinal direction ) And cuts while securing the connecting beams 50 in the longitudinal direction so as to be supported by the H-pile 10 at a predetermined depth inside the secured working space 40, and then the working space 40. ) Is filled again with a filler 60 such as soil and sandbags, the outer peripheral surface of which is the same curvature as the outer peripheral surface of the semicircular base ground 20, and the base ground 20 and its left and right filling bodies ( 60) The inside of semi-circle arch type over the entire upper surface Curving the formwork plate 70, the left and right lower ends of the inner formwork is installed so as to be supported by the connecting beam 50, forming a space portion 80 at an appropriate interval on the outside of the inner formwork plate 70 The outer formwork plate 90 is installed with the same curvature, the lower end is supported on the upper surface of the connecting beam 50, and the space between the inner and outer formwork plates 70, 90 is not in the space 80. Placing the hardened concrete to form a semi-circular arch-shaped lining concrete 100, after the lining concrete 100 is cured to remove the piles and fillings 60 of the base ground 20 therein, the inner and outer formwork By demolding the plates 70 and 90, the basic technical concept of the present invention is realized in that the tunnel upper section is constructed.

As shown in FIG. 3a, first, after the piling is completed, the H-pegs 10 are parallelly spaced at the same interval as the width of the tunnel in the left and right ground where the tunnel is installed, and the lining concrete 100 is installed. While rolling up the ground of the upper toffee layer, while sandwiching the earth plate 30 between the H-stacks 10, the ground is curved to a predetermined depth. At this time, the left and right sides of the ground are piled up to secure a working space 40. Gut to secure a predetermined space.

At this time, it is important to excavate and arrange the ground so that the upper surface of the ground ground 20 formed by flexing the ground is formed in a semi-circle shape with the same shape as the upper section of the tunnel.

This is to make the outer circumferential surface shape of the base ground 20 to be the same as the outer circumferential surface shape of the upper end surface of the tunnel so as to support the inner form plate 70 installed on the upper surface of the base ground 20, which is the tunnel upper end surface. This is because of the reason that the lining concrete of the 100 is molded into a semi-circular arch type.

In addition, the reason for securing the working space 40 on the left and right sides of the base ground 20 in order to secure a space for transporting and installing the connecting beam 50 to the equipment between the H-pile 10.

Therefore, the work space 40 on the left and right sides may be excavated to the depth where the connecting beam 50 is installed, and the other base may be excavated in a semicircular arch type.

On the other hand, the width between the left and right H-peg 10 is equal to the width of the tunnel to be built. Since the H-pile 10 supports the lining concrete 100 of the tunnel after the tunnel construction is completed, the whole is buried in the ground, but when the upper part of the H-peg 10 protrudes, a part of the upper side Can be cut out and buried only in the lower part in the ground.

Meanwhile, the earth plate 30 supported between the H piles 10 may be fitted between the flange and the flange of the H pile 10 as shown in FIG. 4, but FIG. 5, FIG. 6 or FIG. 7A. As shown in the connecting beam 50 is installed between the flange and the flange is preferably supported on the back of the H-peg 10.

After the piling of the H-piles and the excavation work of the ground plate and the earth plate are installed, the T-shaped support plate between the flange and the flange of the H-peg 10 at the position of the predetermined depth of the H-peg 10 as shown in Figure 3b ( 11) are welded, and the connecting beam 50 is installed on the T-shaped support plate 11 between the front and rear H-pile 10, and when the installation of the connecting beam 50 is completed, the left and right sides of the ground ground 20 Filled with a filler 60, such as soil and sand bags on the work space 40 is installed so that the outer peripheral surface is formed in a semi-circular arch shape with the base ground 20 as a whole.

The connecting beam 50 serves to transfer the load of the lining concrete 100 to the H-peg 10 as a structural part installed in the longitudinal direction between the H-peg 10. This connecting beam 50 shows that both ends are supported across the top of the T-shaped support plates 11 welded between the flange and the flange of the front-rear H-pile 10, as in FIGS. 5A-7B.

Therefore, the connecting beam 50 is installed between the flange and the flange of the H-peg 10 to ensure that the load of the lining concrete 100 to be cast in concrete to be transmitted to the H-peg 10.

When the installation of the connecting beam 50 is completed, as shown in Figure 3b and 5 to fill the workspace 40 with the filler 60 again. At this time, the filling body 60 is filled with earth or sand bags, it is important that the outer peripheral surface is filled with the same curvature line as the outer peripheral surface of the semi-circular arch type base ground 20.

The reason for filling the filling body 60 in the work space 40 is to have a supporting force when the inner formwork plate 70 is installed on the upper surface together with the semicircular arch type base ground 20, and the filling body 60 is provided. ) Is a form that fills the working space, and it can be found that if it is divided into several parts or partially used on the outer circumference of the semicircle arch type, it is included in the technical idea of the present invention.

When the filling operation of the working space 40 is completed, as shown in Figure 3c, the base plate 20 and the inner formwork plate 70 that is curved in a semi-circular arch shape over the entire surface of the upper and lower surfaces of the filler 60 on the left and right sides thereof. Will be integrally laid.

The inner formwork plate 70 is made of a flexible material and is supported on the upper surface of the base ground 20 and the filler 60, and the lower left and right ends thereof are supported at the inner end of the connecting beam 50, thereby lining concrete. To serve as an inner panel of the formwork for pouring 100.

On the other hand, when installing the inner formwork 70, it is preferable to also reinforce the reinforcement for lining concrete.

While maintaining the space portion 80 having a predetermined interval on the outside of the inner formwork plate 70 to install the outer formwork plate 90 is installed with the same curvature as the inner formwork plate 70, such an outer formwork plate 90 ) Is installed at regular intervals with the inner formwork to pour concrete therebetween, the left and right lower ends are supported on the outer end of the connecting beam 50 and the middle portion is supported by the earth plate 30 (91) ) To support and to serve as the outer panel of the formwork to mold the lining concrete 100 in a semi-circular shape when placing.

At this time, the left and right lower ends of the outer formwork plate 90 are supported at the outer end of the connecting beam 50 and the center part is supported by the support 91, which is not easy to install a support on the left and right slopes in the past. Otherwise, it can be simply supported.

On the other hand, since the space 80 between the inner and outer formwork is a space where the lining concrete 100 is eventually formed, it is preferable to give the thickness of the space 80 to the structural strength according to the site. In other words, when the load is heavy according to the amount of toppings on the upper part of the tunnel, the lining concrete 100 needs to be thickly constructed, and when the load is relatively light, it is necessary to thinly construct it.

Although not shown for concrete molding of a predetermined required thickness at a predetermined position of the space portion 80, it is a matter of course that spacers can be installed between the inner formwork plate and the outer formwork plate.

When the formwork consisting of the inner and outer formwork is completed, the non-hardened concrete is poured into the form inner space 80 to form a semi-circular arched lining concrete 100.

When laying concrete for forming lining concrete, the external formwork plate 90 may be divided into several pieces, but it is preferable to use two external formwork plates 90 on the left and right except the center part, and the center part is filled with concrete. It can be finished in the form of application.

The left and right lower ends of the molded concrete lining 100 are supported by the connection beam 50. Therefore, the load of the lining concrete 100 is transmitted to the ground through the connecting beam 50 and the H-peg 10.

Therefore, since the inner formwork plate 70 is supported on the upper surface of the base ground 20 and the filling body 60, unlike the conventional support structure, there is no need to install the support structure, thereby increasing workability and economical efficiency. Becomes

When the lining concrete 100 is hardened, as shown in FIG. 3d, the inner base 20 is excavated to a predetermined depth, and the base ground 20 of the semicircular arch type supporting the inner form is excavated and left and right sides. The lining concrete 100 is molded by removing the filler 60 filled in the work space and demolding the inner and outer formwork plates 70 and 90.

Thereafter, when filling the upper part of the lining concrete 100, as shown in Figure 3e, the left and right sides of the lining concrete 100 is filled with polyethylene styropole (a), and the soil (b) is filled on the upper surface of the back filling.

Here, the reason for filling the left and right sides of the lining concrete 100 with polyethylene styropol (a) is to reduce the load on the tunnel upper surface by filling with a light material.

On the other hand, if necessary, cut the upper portion of the H-pile 10 and backfills the earth and sand, wherein the position to cut the upper portion of the H-pile 10 is preferably made on the upper side of the filling portion 60 is filled. This is to prevent the earth pressure of the ground that is not excavated outside of the H-pile 10 does not affect the upper section of the tunnel.

Thereafter, as shown in Figure 3f, the lower end portion of the lining concrete 100 is constructed by a conventional tunnel construction method, or as shown in Figure 6 by laminating a ready-made concrete panel (c) surface of cement mortar or shotcrete Clean up irregularities and voids.

Thereafter, as shown in FIG. 3F, after the sheet waterproofing is performed in the same manner as in the general tunnel construction, the secondary construction is performed while continuing the construction according to the tunnel construction.

As described above, the present invention is a method that can be applied when the toffee at the point where the tunnel is constructed is constructed, the tunnel upper section is first constructed, and then the inner ground is excavated to construct the tunnel through the tunnel construction section. To build.

Therefore, by installing vertical support beams in the left and right sides of the cross section of the tunnel to be constructed in a shallow toffee during tunnel excavation construction, the upper lining construction is performed in advance of the main construction, and the construction can be performed without cutting much soil.

As a result, slopes are stabilized in areas with shallow toffees such as tunnel entrances and valleys, and there is no risk of landslides. Minimization of destruction is possible, and after construction, accidents caused by freezing of roads are prevented.

Thus, the present invention, first, the present invention does not involve large-scale earthwork to build a tunnel, so that the slope of the entrance and exit of the tunnel is stabilized around the valley, and there is no risk of safety accidents.

Second, the present invention, because the soil plate 30 is inserted into the left and right H-pile 10 to prevent the collapse of the ground to excavate and fill the soil, the earthwork volume is drastically reduced, thereby reducing the construction cost and shortening the overall construction period. Giving effect,

Third, since the ground ground 20 is used to support the formwork, and the ground ground 20 is excavated after the lining concrete 100 is poured, the conventional ground lining and the support base were hypothesized for the tunnel lining construction. Contrary to this, there is no need for support, which reduces the ease of construction and the cost of construction.

Fourth, since the cut area is drastically reduced compared to the prior art has the effect of reducing the destruction of the natural environment.

As described above, the present invention can not only stabilize the slope by reducing unnecessary cut and fill amount, but also shorten the construction period and reduce the construction cost as a whole, and also to form the upper section of the tunnel. It is a useful invention to simplify the construction work by using the ground to support the formwork.

Claims (7)

H-piles 10 are driven to the left and right sides of the tunnel construction point at regular intervals, and the cuts are bent so as to form a semi-circular base ground 20 between the inner sides of the H-piles 10, the H-peg While cutting the work space 40 to the appropriate depth while inserting the earth and sand prevention earth plate 30 on the back of the, the H-peg 10 at a predetermined depth inside the secured work space 40 After installing the connecting beams 50 in the longitudinal direction to be supported in, fill the working space with the filler 60 to form the outer circumferential surface of the tunnel, and after installing a flexible formwork on the curved base ground and the surface of the filler After placing the concrete to form a semi-circular arch-shaped lining concrete 100, after the lining concrete 100 is cured, remove the piles and fillings 60 of the inner ground 20 and the inner and outer formwork plate ( Demolding 70) (90) Tunnel construction method of toffee shallow areas with features that axis. The tunnel construction method according to claim 1, wherein the filling body (60) is made of soil and sandbags. The tunnel construction method of claim 1, wherein the formwork is made of plywood. According to claim 1, wherein the connecting beam 50 is installed on the upper end of the T-shaped support plate 11 is welded between the flange and the flange of the H-pile 10, the toffee is shallow Local tunnel construction method. The method of claim 1, wherein the lining concrete (100) is a tunnel construction method in the toffee shallow region, characterized in that the lower end is constructed so that the load is transmitted to the connection beam (50). The tunnel construction method of claim 1, wherein after filling the upper and left sides of the lining concrete 100 with polystyrene styropol (a), the earth and sand (b) are refilled at an appropriate height. . According to claim 1, Topi is characterized in that the bottom of the lining concrete 100 is laminated with a ready-made concrete panel (c) between the H-pile 10, filling the irregularities and voids with cement mortar Tunnel construction in shallow areas.