KR102249947B1 - Trenchless method using recoverable horizontal pile and inclination angle of excavation surface - Google Patents

Abstract

In the non-cracking method in which horizontal excavation is carried out in the ground without excavating the ground, it is possible to recover while using a horizontal pile to suppress settlement, deformation, and collapse occurring in the upper ground or the front ground, and the strength of the ground is constant. A retrievable horizontal pile that can improve the safety of the excavation surface by constructing it with an inclined excavation surface in consideration of and a non-drilling method using the inclination of the excavation surface is disclosed.

Description

Non-cracking method using recoverable horizontal pile and inclination of excavation surface{TRENCHLESS METHOD USING RECOVERABLE HORIZONTAL PILE AND INCLINATION ANGLE OF EXCAVATION SURFACE}

The present invention relates to a non-cracking method using a recoverable horizontal pile and an inclination of an excavation surface. More specifically, in the non-cracking method in which horizontal excavation is carried out in the ground without breaking the ground, it is possible to recover while using a horizontal pile so as to suppress settlement, deformation, and collapse occurring in the upper ground or the front ground. It relates to a recoverable horizontal pile that can improve the safety of the excavation surface by constructing it with an inclined excavation surface considering the strength constant of and a non-drilling method using the inclination of the excavation surface.

Due to the performance improvement and new construction of transportation facilities, parallel and crossover of transportation facilities frequently occur on the ground and underground. In particular, roads using a non-breaking method for the construction of deep roads, subways, and railroads due to the expansion of urban areas. , A method of horizontal excavation of the lower ground such as subways and railways is required.

For example, in the construction of a road crossing the railroad, in order not to interfere with railroad operation, the lower ground of the railroad is horizontally excavated, and an underground tunnel structure is constructed in the horizontally excavated space so that vehicles can pass.

Therefore, it is referred to as a non-cracking method because the underground tunnel structure construction is performed under the railroad without cutting the ground surface.

However, even in such a non-cracking method, it is common that the upper ground is relaxed due to horizontal excavation, so that some subsidence and deformation occur, and a method of minimizing this is required. In particular, there is a need to efficiently control the relaxation of the upper ground and the collapse of the front ground during horizontal excavation in the low-topic section.

Figure 1a shows a flow chart of a conventional construction method of a non-cracked structure.

In other words, it can be seen that the construction start (S) and the end point (E) are constructed in the form of a vertical sphere, and an underground tunnel structure that crosses the ground under the railroad is being constructed.

In other words, it can be seen that the tip shoe 12 is used to press-fit the hollow pipe modules 11 and 13 constituting the underground tunnel structure from the starting point to the end point in a traction method.

At this time, as the end shoe is pulled from the end point, the tip shoe 12 is pressed into the ground.In this press-in process, the upper ground and the front ground are relaxed and settling occurs.In order to prevent this, the steel pipe multi-stage grouting 14 ), it can be seen that the relaxation of the front and upper ground is controlled.

However, since the steel pipe multi-stage grouting 13 must be constructed by arranging it radially forward while having a minimum angle, it is inevitably a factor of delay and increase in construction cost, and because it requires grouting, environmental pollution is inevitable. In the case of obstacles, there is a limit that construction is very difficult.

Figure 1b shows a construction state diagram of a horizontal small steel pipe in constructing a conventional underground tunnel structure.

That is, in the initial construction of the tunnel excavation surface, the small-diameter steel pipes 30 are horizontally spaced apart from each other for reinforcement of the excavation surface, and press-fit along the tunnel section in a type of loop form, and a steel support hole 50 is installed inside. You can see that there is.

At this time, the reason for using small-diameter steel pipes is that when large-diameter steel pipes are used, large-sized equipment is required, which lowers economic efficiency and workability, and only an extension length to reinforce the excavation surface is required. Because.

Figure 1c shows a construction diagram of a conventional SEM method.

The SEM (Super Equilibrium Method) method is a non-cracking method, so that the front ground and the upper ground are relaxed and not settled during the press-fitting process, the SEM file 61 is moved from the top of the front shoe (62, including the enclosure) to the front of a certain length (5M). ,After) install so that it is extended, and the upper ground (①②③) is minimized by the SEM file 61, and the front ground (④⑤) under the SEM file 61 does not enter the tip shoe excavation surface. It can be seen that (63) is being installed.

At this time, the SEM file 61 is press-fit in the longitudinal direction forward and horizontally using a small-diameter steel pipe (100-130 mm in diameter), but is disposed so as to be spaced apart from each other in the transverse direction. It should have a diameter, but it is designed and constructed to have a distance and length that can support the maximum load without being broken by the applied load.

However, since the SEM file 61 is installed outside the tip shoe 62, it cannot be finally recovered, and after the horizontal excavation is completed, it is inevitable to be sacrificed in the ground, and when the front pressure plate 63 is used, workability will be degraded. In addition, there is a problem that construction management is not easy because there is a possibility of a safety accident in which the excavation surface collapses during construction.

Korean Patent No. 10-1858223 (Name of invention: friction reduction device for construction of non-cracked structures and construction method for non-cracked structures using the same, publication date: May 16, 2018) Republic of Korea Patent No. 10-1665515 (Name of invention: construction method and structure of multi-stage tunnel with straight boring steel pipe without cutting the original ground, publication date: October 24, 2016)

Therefore, the present invention is possible to recover while applying a small-diameter steel pipe (diameter 100-300mm) to minimize ground deformation such as ground surface subsidence occurring in the conventional medium and large-diameter (diameter 800-1000mm) steel pipe press-in step. This is a technical task to solve the provision of a recoverable horizontal pile that can minimize ground environmental pollution due to not using cement grouting and a non-cracking method using the inclination of the excavation surface.

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The non-cracking method using the inclination of the recoverable horizontal pile and the excavation surface of the present invention for solving the above problem,

(a) installing the horizontal pile on the inner surface of the upper part of the enclosure via the tip shoe so that the horizontal pile supports the ground load and the overhead load under relaxation load of the upper ground (G1); And (b) horizontal excavation of the ground by pressing the front shoe into the front ground (G2) and extending the enclosure forward together, but excavation using the ground strength constant of the front ground (G2) so that the excavation surface is safe without a reinforcement. Including; maintaining the slope of the surface;
The horizontal pile has one end hinged to the front shoe, and the front end is press-fitted into the front ground and installed so that recovery is possible, and a number of small-diameter piles are integrated with each other to support the load acting from the upper ground. It is a small diameter pile body with a diameter of 100~300mm,
As the inclination of the excavation surface is secured, the ground load and the overhead load during the relaxation load of the upper ground G1 borne by the horizontal pile can be controlled.

Also preferably,

In the step (a), the housing is integrally connected to the rear of the front shoe, so that the front shoe and the housing are horizontally pressed, so that the construction of the underground tunnel structure is performed by horizontal excavation.

Also preferably,

In the step (a), the horizontal pile has a constant extension length in the longitudinal direction, is disposed so as to be in contact with each other or spaced apart at a predetermined interval in the transverse direction, one end is fixed to the inner side of the front shoe, and the front end is the front ground ( It is constructed so that it is pressed into G2).

Also preferably,

In the step (a), the horizontal pile is constructed by reviewing the longitudinal section safety of the horizontal pile, reviewing the cross-sectional safety of the horizontal pile, and then examining the excavation surface inclination.

Also preferably,

The longitudinal safety of the horizontal pile 120 is determined by randomly determining the diameter of the horizontal pile, evaluating the load (unit load) received by one horizontal pile in the relaxation area of the upper ground of the horizontal pile, and the cross-sectional stiffness of one horizontal pile It is made to be greater than the stress caused by the applied unit load, and by evaluating the interval at which the unit load becomes the maximum, the stiffness of the cross section of one horizontal pile is greater than the load in the overlapping relaxation zone.

Also preferably,

The cross-sectional stability of the horizontal pile is such that the bending stiffness of the horizontal pile is greater than the ground load and the overhead load under the relaxation load of the upper ground, and the pull-out load of the horizontal pile is greater than the surrounding friction force.

Also preferably,

The excavation surface inclination is made so that the excavation surface does not collapse by calculating the final horizontal excavation length of the horizontal pile and considering the ground strength constant according to the cover height.

Also preferably,

The excavation surface inclination is determined in consideration of the depth at which the underground tunnel structure is installed at 45 degrees + Φ/2.

Also preferably,

The excavation surface inclination is achieved by maintaining a front shoe inclination of 40 to 75 degrees.

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The present invention can minimize ground disturbance by adopting an inclined excavation surface in consideration of the strength constant of the ground and reinforcement of the ground by horizontal installation of the horizontal pile, and more efficient non-cracked underground through improvement of the excavation surface safety and construction speed. It will be possible to provide a cross-section construction method.

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1a is a flow chart of a conventional method for constructing a non-cracked structure,
Figure 1b is a construction state diagram of a horizontal small steel pipe in the conventional tunnel construction,
1c is a construction diagram of a conventional SEM method
2 and 3 are a construction concept diagram of a non-cracking method using a recoverable horizontal pile of the present invention and an inclination of the excavation surface,
Figure 4 is a design method of a non-cracking method using a recoverable horizontal pile of the present invention and the inclination of the excavation surface;
5 and 6 are flow charts of a non-cracking method using a recoverable horizontal pile of the present invention and an inclination of the excavation surface.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art can easily implement the present invention. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and similar reference numerals are attached to similar parts throughout the specification.

Throughout the specification, when a part "includes" a certain component, it means that other components may be further included rather than excluding other components unless specifically stated to the contrary.

[Constitution of the non-cracking method using the recoverable horizontal pile of the present invention and the inclination of the excavation surface]

2 and 3 are a conceptual diagram of the construction of the non-cracking method using the inclination of the recoverable horizontal pile and the excavation surface of the present invention, and FIG. 4 is a design method of the non-cracking method using the inclination of the recoverable horizontal pile and the excavation surface of the present invention. It shows the degree.

In the non-cracking method using the recoverable horizontal pile and the inclination of the excavation surface, the horizontal pile 120 is installed so as to be recoverable, so that it can be recovered later.

Accordingly, the non-breaking method according to the present invention is made by including the front shoe 110, the horizontal pile 120, the excavation surface 130, and the enclosure 140, as shown in FIGS. 2 and 3.

First, the front shoe 110 is necessary for horizontal excavation of the ground, as shown in FIGS. 2 and 3, and as the front shoe is pressed in the front, the front shoe is formed in a wedge shape, and the front shoe is formed in a wedge shape, and the rear of the front shoe is a housing 140 ) Is integrally connected, so that the front shoe 110 and the enclosure 140 are horizontally press-fitted, so that the construction of the underground tunnel structure by horizontal excavation is made.

The horizontal pile 120 is formed as a small diameter pile body extending horizontally to the front from the inner side of the housing 140 via the front end shoe 110, especially as shown in Figs. It is a feature.

That is, in the related art, since the horizontal pile 120 is installed on the upper surface of the front end shoe 110 to extend forward, it cannot be in a state that can be recovered from the inside of the enclosure 140, but the present invention is the horizontal pile 120 In a state that is installed on the upper inner surface of the housing 140 via the tip shoe 110, it is extended to the front so that it can be recovered at a later time.

Accordingly, in the horizontal pile 120, a plurality of small-diameter piles are integrated with each other to construct a small-diameter pile body having a function of supporting a load acting from the upper ground, for example, steel pipes having a diameter of about 100 to 300 mm are separated from each other in the transverse direction. It will be integrated and constructed.

This small-diameter pile body is constructed as a horizontal support so as to support the upper ground (G1) in front of the tip shoe 110, and when the front direction is called the longitudinal direction, it has a constant length in the longitudinal direction, and the transverse direction It is in contact with each other or is arranged to be spaced apart by a certain distance, one end is fixed to the inner side of the front shoe, and the front end is constructed to be press-fit into the front ground (G2).

As a result, one end of the horizontal pile 120 is hinged to the tip shoe 110, and the tip is press-fitted into the front ground and fixed, so that it can support the relaxation load (ground load) and the overhead load of the upper ground during the construction process. You can see that it will be possible.

Specifically, the horizontal pile 120 evaluates the load received by one small-diameter pile to determine the diameter of the small-diameter pile with required stiffness, and evaluates the interval that can support the maximum load to determine the construction interval of the small-diameter pile. It is designed in a way that evaluates the safety of the small-diameter pile body by a plurality of small-diameter piles so that they can sufficiently resist pulling without being broken by the relaxation load (ground load) and the overhead load of the upper ground.

The excavation surface 130 is an excavation surface (the excavation surface of the front ground formed by excavation) because the front ground G2, which is the lower ground of the horizontal pile 120, is also relaxed during the excavation process, as shown in FIGS. 2 and 3. It is about to collapse.

The excavation surface 130 is formed through blasting and equipment such as an excavator, which is not shown, but naturally occurs during the construction process.

At this time, since the excavation surface has a fairly large cross-sectional area, it is formed to be naturally inclined according to the construction sequence by adopting a method of excavating first from the upper section and then excavating the lower section.

However, since the inclined excavation surface is not safe, a conventional reinforcement is additionally installed (excavation surface reinforcement). Such a reinforcement is a kind of support material and takes a lot of time and cost.

Accordingly, the present invention controls the inclination so that the excavation surface 130 can be stabilized by self-standing. However, the lower the inclination, the more stable it is, but it is not easy to construct the inclination randomly low in the construction process, so separate reinforcement is required. It becomes important to manage the slope of the excavation surface that does not collapse while making it unnecessary.

Accordingly, in the present invention, since the ground load on the top of the excavation surface of the tip shoe 110 and the overhead load by the external force act, the optimum slope is determined using the result of performing the excavation surface stability analysis based on this.

For example, according to FIG. 4, the safety factor (securing cost and efficiency based on the safety factor 1) and the inclination according to the height of the excavation surface are calculated in advance, for example, an inclination angle of about 38 degrees (the angle of the excavation surface inclined upward from the horizontal surface, the acute angle) ) To maintain the excavation surface slope that can achieve stabilization without reinforcement, so that the excavation surface slope is managed.

At this time, the slope graph according to FIG. 4 is prepared and constructed by reflecting the ground strength constant that varies from site to site.

The enclosure 140 is integrally connected to the rear of the tip shoe 110, as shown in FIGS. 2 and 3, so that when the tip shoe 110 is pressed forward, the enclosure 140 also moves forward as long as the tip shoe is pressed. The enclosure 140 continuously integrated so as to form an underground tunnel structure, and the horizontal pile 120 is hinged to the upper inner surface of the first enclosure 140.

Accordingly, the present invention is a method of using the inclination angle of the horizontal pile 120 that is recoverable by the non-cracking method and the inclination of the excavation surface that is safe without reinforcement, so that the horizontal pile 120 can be prevented from settling and deformation due to relaxation of the upper ground. It can be seen that it is a construction method capable of securing economic feasibility by ensuring the maximum installation interval of the pile 120, and managing the end face through management of the inclination angle of the front excavation surface.

[Recoverable horizontal pile and non-cracking method using the inclination of the excavation surface]

5 and 6 are diagrams showing a design review flow chart and a construction flow chart of a non-cracking method using a recoverable horizontal pile and an inclination of the excavation surface of the present invention.

First, looking at the matters to be reviewed in the design stage prior to the non-drilling method according to the present invention, as shown in FIG. 5, it can be seen that the cover height from the ground surface to the horizontal excavation center axis is first determined in horizontal excavation in the ground.

Since such a cover height is a value that is determined according to the site conditions, an underground tunnel structure should be constructed so that subsidence due to ground relaxation and collapse of the excavation surface do not occur at any cover height.

Accordingly, first, as shown in FIG. 5, first, the longitudinal section safety of the horizontal pile 120 is reviewed, second, the cross-sectional safety of the horizontal pile 120 is reviewed, and third, the preliminary review work is conducted by reviewing the excavation surface inclination. You can see that it will come true.

First, the longitudinal safety of the horizontal pile 120 is determined by arbitrarily determining the diameter of the horizontal pile 120, and the horizontal pile 120 in the relaxation area (using an arithmetic formula for determining the relaxation area of the upper ground of the horizontal pile 120). ) Evaluating the load (unit load) received by one, and if the sectional stiffness of one horizontal pile 120 is greater than the stress due to the unit load acting, the interval at which the unit load becomes the maximum is evaluated and compared to the overlapped relaxation zone load. On the premise that the cross-sectional rigidity of one horizontal pile 120 is increased, the cross-sectional safety is examined.

Next, the cross-sectional safety of the horizontal pile 120 is such that the bending stiffness of the horizontal pile 120 is greater than the relaxation load (ground load) and the overhead load of the upper ground, so that the pulling load of the horizontal pile 120 is greater than the surrounding friction force. It will be reviewed in a way that makes it possible to do so.

In the final examination of the excavation surface inclination, the final horizontal excavation length of the horizontal pile 120 is calculated, and as shown in FIG. 4, the excavation surface does not collapse in consideration of the ground strength constant according to the cover height, that is, excavation with a safety factor of 1. This is done by examining the surface slope.

Accordingly, when the lateral safety, longitudinal safety and excavation degree of the horizontal pile 120 are reviewed, the number of installations, extension length, and lateral width of the horizontal pile 120 are determined, and the excavation surface slope is determined.

Accordingly, according to FIG. 6,

First, the housing 140 and the front shoe 110 are connected in a fixed hinge form to the inner surface of the housing 140 through the horizontal pile 120 through the inside of the front shoe in the initial setting state, and the front end It can be seen that it will be installed in a fixed state on the ground.

Accordingly, since the horizontal pile 120 is located inside the enclosure 140, it can be seen that it can be recovered when the construction is completed.

Next, the front end shoe 110 is extended forward to prepare for front excavation while the upper ground is not settled by the enclosure 140 and the horizontal pile 120.

Next, as the front shoe 110 expands forward, the relaxed front ground is excavated, and at this time, the excavation surface can be stabilized by securing the excavation surface inclination based on, for example, a case where the safety factor is 1. Able to know.

Next, it can be seen that horizontal excavation is performed by advancing the housing 140 and the front shoe 110 together.

Therefore, if the horizontal excavation is repeated as necessary and the final horizontal excavation is carried out, settlement and deformation by the relaxation of the upper ground (G1) do not occur, and the excavation surface by the front ground (G2) also achieves safety boots without additional reinforcement. It is possible to construct an underground tunnel structure by rapid and economical horizontal excavation.

As a result of using small-diameter (100-300mm in diameter) steel pipes as horizontal piles, the relaxation area of the upper ground (G1) is reduced compared to the case of using medium-diameter and large-diameter steel pipes, and it can be recovered and reused. Economical,

Unlike conventional, horizontal piles are placed and pressed in horizontally, so there is no need for separate grouting, so the type of work is simplified and the damage from environmental pollution can be minimized. Due to this, the construction speed is increased and safety can be secured.

The excavation surface slope is made so that the excavation surface does not collapse by calculating the final horizontal excavation length of the horizontal pile 120 and considering the ground strength constant according to the cover height, for example, 45 degrees + Φ/2. (Φ: Ground friction angle) This is done by maintaining the tip shoe inclination of 40 to 75 degrees, and the value can be determined in consideration of the depth at which the underground tunnel structure is installed.

As a result, it can be seen that the present invention is provided with a mechanism for controlling the ground load and the overhead load under the relaxation load of the upper ground G1 borne by the horizontal pile 120 as the inclination of the excavation surface is secured.

The above description of the present invention is for illustrative purposes only, and those of ordinary skill in the art to which the present invention pertains will be able to understand that other specific forms can be easily modified without changing the technical spirit or essential features of the present invention. will be. Therefore, it should be understood that the embodiments described above are illustrative in all respects and are not limiting. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as being distributed may also be implemented in a combined form.

The scope of the present invention is indicated by the claims to be described later rather than the detailed description, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present invention. do.

110: tip shoe
120: horizontal pile
130: excavation surface
140: enclosure

Claims (10)

(a) Steps so that the horizontal pile 120 is installed on the upper inner surface of the enclosure 140 via the tip shoe 110 so that the horizontal pile 120 supports the ground load and the overhead load under the relaxation load of the upper ground (G1). ; And
(b) Horizontal excavation of the ground by pressing the front shoe 110 into the front ground (G2) and extending forward with the enclosure 140, but the ground strength of the front ground (G2) so that the excavation surface is safe without a reinforcement Including; maintaining the inclination of the excavation surface 130 by using an integer,
The horizontal pile 120 has one end hinged to the front end shoe 110, and the front end is press-fitted into the front ground and fixed to allow recovery,
It is a small-diameter pile body with a diameter of 100 to 300 mm with the function of supporting the load acting from the upper ground by a number of small-diameter piles integrated with each other.
By securing the inclination of the excavation surface 130, the ground load under the relaxation load and the overhead load of the upper ground G1 borne by the horizontal pile 120 are controlled using a recoverable horizontal pile and the inclination of the excavation surface. Non-breaking method. The method of claim 1,
In step (a),
To the rear of the front shoe, the body 140 is integrally connected, so that the front shoe 110 and the body 140 are pressed horizontally, and a recoverable horizontal pile and excavation surface to allow the construction of an underground tunnel structure by horizontal excavation. Non-cracking method using the inclination of. The method of claim 1,
In the step (a), the horizontal pile 120 has a constant extension length in the longitudinal direction, and is disposed so as to be in contact with each other or spaced apart at a predetermined interval in the transverse direction, and one end is fixed to the inner surface of the front shoe Is a non-cracking method using the inclination of the excavation surface and the recoverable horizontal pile that is constructed to be pressed into the front ground (G2). The method of claim 1,
In the step (a), the horizontal pile 120 is
After reviewing the safety of the longitudinal section of the horizontal pile 120, reviewing the safety of the cross section of the horizontal pile 120, and reviewing the inclination of the excavation surface, a recoverable horizontal pile and the inclination of the excavation surface are used to make the construction work. . The method of claim 4,
The longitudinal safety of the horizontal pile 120 is
The diameter of the horizontal pile 120 is arbitrarily determined, the load (unit load) received by one horizontal pile 120 in the relaxation area of the upper ground of the horizontal pile is evaluated, and the unit load at which the cross-sectional stiffness of one horizontal pile acts. Non-cracking using the inclination of the excavation surface and the recoverable horizontal pile made so that the cross-sectional stiffness of one horizontal pile 120 is greater than the overlapping relaxation area load by evaluating the interval at which the unit load becomes the maximum and Method. The method of claim 5,
The cross-sectional safety of the horizontal pile 120 is
The bending stiffness of the horizontal pile 120 is greater than the ground load and the overhead load under the relaxation load of the upper ground, and the pull-out load of the horizontal pile 120 is made larger than the surrounding friction force. Method. The method according to claim 5 or 6,
The excavation surface slope is
Calculate the final horizontal excavation length of the horizontal pile 120, and considering the ground strength constant according to the cover height, so that the excavation surface does not collapse, a recoverable horizontal pile and a non-breaking method using the inclination of the excavation surface. The method of claim 1,
The inclination of the excavation surface is determined by considering the depth at which the underground tunnel structure is installed at 45 degrees + Φ/2, and a non-cracking method using the inclination of the excavation surface and a recoverable horizontal pile. The method of claim 8,
The inclination of the excavation surface is a non-drilling method using a recoverable horizontal pile and an inclination of the excavation surface to be reviewed by maintaining a tip shoe inclination of 40 to 75 degrees. delete

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