KR101257854B1 - The method of constructing lining concrete in full scale underground storage - Google Patents

Abstract

The present invention is to improve the workability and quality of the lining concrete by constructing a large-scale underground cavities of the end of the lining concrete and the bench (bench) excavation at the bottom of the end, and performing the lining concrete for the entire bench after the remaining bench excavation, The present invention relates to a method of constructing lining concrete in large-scale underground cavities that can reduce construction costs and air.
The present invention, the first step of setting the end of the lining concrete vibration tolerance standards according to the excavation of the bench 1 (Bench 1) of the large underground underground after the excavation and reinforcement of the top heading or gallery in a large underground cavity; A second step of calculating an optimum separation distance between the lining concrete and the excavation; A third step of concurrently constructing the excavation of the bench 1 at the lower end of the position away from the end of the top end by the spacing calculated with the lining concrete construction of the top heading, the gallery; And a fourth step of placing lining concrete for the entire bench after the excavation of the bench 2 or the bench 3 at the bottom of the bench 1. to provide.

Description

Method of constructing lining concrete in full scale underground storage

The present invention relates to a method for constructing lining concrete of large-scale underground cavities, and more particularly, to excavating the bench 1 together with the construction of lining concrete (Gallery, Top Heading) when constructing concrete structures of large-scale underground cavities. In parallel, the present invention relates to a method for constructing lining concrete in large-scale underground cavities that can reduce construction costs and air while improving quality with overall constructability.

In recent years, the construction of underground space has been steadily increasing for the purpose of expanding social infrastructure, supply and demand of materials, and stable supply of energy resources.

Excavation and support design that considers rock condition, direction and size of initial pressure, shape and arrangement of cavity is essential for stable excavation and maintenance of large-scale underground cavities with larger cross sections than road and railway tunnels. have.

Existing large-scale underground cavities are mostly underground storage bases for the purpose of storing petroleum or agricultural and marine products, and the excavation and reinforcement processes have been mainstream. However, as the role of large-scale underground cavities is expanded to compressed air or LNG underground storage, concrete structures such as lining, in addition to excavation and reinforcement processes, are also considered for design and construction.

A large underground cavity is a cross section of a four-lane road tunnel or more, and is composed of a top heading or gallery, bench 1, bench 2, bench 3, and the like as shown in FIG. In such a large-scale underground cavity, concrete lining process can be generally considered after the excavation and reinforcement process as in tunnel construction, as shown in Figure 1, but it is necessary to install the shear surface at once as in tunnel construction And difficulties in quality control.

In large underground cavity, the problem of shearing lining is that the casting time is long due to the large amount of casting, the compaction is not done properly, and the strength may be lowered. have. In addition, the construction and the reinforcing reinforcement work should be performed by assembling more than 20m bogie, so that not only construction property but also safety is reduced.

In order to solve the problem of shearing the shear surface, it may be said that it is preferable to perform step-by-step casting by dividing the top end portion and the side wall portion. In addition, since the large-scale underground cavity excavation is completed, the lining is placed by dividing into the top end and the side wall, and thus the top end lining concrete construction has a problem similar to that of the shear surface lining concrete construction. That is, to perform the waterproof and lining reinforcement work on the top end is required to work more than 20m, the workability and safety is reduced. In addition, when the end of the lining concrete construction formwork is formed at a height of 20m or more and the pouring process is performed, there is a problem in poor workability.

Therefore, the present invention has been proposed to solve the above-mentioned general problems, the construction of a large-scale underground joint top end lining concrete and bench 1 excavation of the bottom end (bench) in parallel, and the rest of the bench after excavation to the entire bench The purpose is to provide a method of constructing lining concrete in large-scale underground cavities that can improve the workability and quality of lining concrete and reduce construction costs and air by performing the lining concrete construction.

In addition, the present invention establishes the vibration tolerance standard of the optimized lining concrete when building a large underground cavity and calculates the proper separation distance of the lining concrete structure from the excavation surface to prevent the strength of the concrete structure is lowered by the vibration caused by the excavation Another object is to provide a method for constructing lining concrete in large-scale underground cavities to ensure high quality and stability.

In order to achieve the above object, the present invention, after the excavation and reinforcement of the Top Heading or Gallery in a large-scale underground cavities, the ground-end lining concrete vibration tolerance criteria according to the excavation of Bench 1 (Bench 1) of a large-scale underground cavities Setting a first step; A second step of calculating an optimum separation distance between the lining concrete and the excavation; A third step of simultaneously constructing the excavation of the bench 1 at the lower end of the position away from the end of the ceiling by the spacing calculated with the lining concrete construction of the ceiling; And a fourth step of placing lining concrete for the entire bench (Bench) after the excavation of the bench 2 (Bench 2) and the bench 3 (Bench 3) at the bottom of the bench 1 to provide.

Here, the vibration limit of the lining concrete of the first step is set to the vibration tolerance by dividing within 24 hours and more than 24 hours according to the degree of curing of the lining concrete.

In addition, the third step includes installing a dustproof under the lining concrete to block the shock wave caused by the blasting on the lining concrete structure of the top end.

In addition, the third step is a first process of dividing the area of the bench 1 into the mechanical excavation section and the center blasting section on both sides of the top end; A second process of dividing the blasting section of the bench 1 into two blasting excavations; And a third process of mechanically excavating a predetermined section of the bench 1.

As described above, according to the features of the present invention, the following effects are obtained.

In large-scale underground cavities, lining concrete at the top end is installed in parallel with the excavation of the bench,

First, it is possible to improve the workability and safety of lining concrete construction.

After the excavation of the entire underground cavities in the large underground cavities, when the lining concrete construction is carried out, the high altitude work will be carried out on structures of 20m or more. This high work is less workability and safety compared to the general tunnel lining concrete construction is carried out in 7 ~ 9m. On the other hand, the present invention can improve the workability and safety by providing a work environment similar to the general tunnel lining concrete construction.

Second, the cost of lining concrete construction can be reduced.

After excavating the entire large underground cavities, the construction of top heading and gallery lining concrete requires more than 20m of concrete placing structures or special structures. However, as in the present invention, by constructing the top-end lining concrete with Bench 1 excavation in parallel, the top-end lining concrete can be constructed in a structure similar to the lining concrete placing work of general tunnel construction, thereby reducing the construction cost.

Third, the air is shortened.

In general, large underground cavities that require lining concrete are excavated, reinforced, and constructed in concrete. The present invention can reduce the bench 1 excavation air in the overall construction period by constructing the top-end lining concrete and Bench 1 excavation in parallel.

Fourth, the quality of the lining concrete is improved.

In the construction of the lining of the top end, when the shearing is completed at the height of 20m or more, the compaction quality is poor. On the other hand, the present invention, since the lining concrete is poured after the excavation of the Top Head (Gallery), the same quality as the general tunnel lining concrete can be obtained to improve the quality of the lining concrete.

1 is a general process flow chart for constructing lining concrete after excavation and reinforcement in the same manner as the existing tunnel construction method when constructing a large underground cavity;
Figure 2 is a flow chart for explaining the parallel construction method of lining concrete and bench in a large-scale underground cavity according to the present invention,
3 is a cross-sectional view of the construction of lining concrete in a large-scale underground cavity according to the present invention,
Figure 4 is a parallel construction of the end-lining concrete placing and bench 1 (Bench 1) excavation in a large-scale underground cavity according to the present invention, the bench 1 excavation divided into blasting excavation and mechanical excavation and divided by blasting excavation in two Construction concept,
Figure 5 is a concept of excavation of Bench 1 showing the process of excavating Bench 1 in the rear of the optimum separation distance during the top heading (gallery) lining concrete pouring in the present invention,
6 is a process flowchart for constructing lining concrete in a large-scale underground cavity according to the present invention;
Figure 7 is an explanatory diagram for reducing the amount of delay per delay and excavation length used in the vibration reduction scheme in the present invention.

The above-mentioned objects, features and advantages will become more apparent from the following detailed description in conjunction with the accompanying drawings. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Lining concrete construction method in a large-scale underground cavity according to the present invention by constructing the lining concrete of the top end and the bench 1 (bench 1) excavation at the bottom of the ceiling end, and by performing the lining concrete construction for the entire bench after the remaining bench excavation It is implemented to improve the workability and quality of lining concrete.

Figure 2 is a flow chart for explaining the excavation parallel construction method of lining concrete and bench in a large-scale underground cavity according to the present invention, Figure 3 is a cross-sectional view of the construction of lining concrete in a large-scale underground cavity according to the present invention.

As shown in the figure, the present invention first performs the excavation and reinforcement of the top heading (Top Heading or Gallery) in the large-scale underground cavities (210, 220), and then the top-end lining according to the excavation of the bench 1 (Bench 1) of the large-scale underground cavities Set the vibration tolerance of the concrete 410 (S110).

In the embodiment of the present invention, the vibration tolerance of the lining concrete is set so that the vibration caused by the excavation does not occur in the strength of the concrete structure while the vibration caused by the excavation is referred to.

Theoretically, the vibration tolerance for concrete structures can be expressed by the relationship between the lining concrete allowable tensile stress, the density of the medium (rock), and the seismic velocity. When blasting, the shock wave is transformed into an elastic wave, propagates along the medium (rock) and affects the structure. At this time, the stress received by the structure is the tensile stress according to the tensile fracture theory.

[Calculation Formula 1]

σ = ρ C V

Where σ is the stress applied to the concrete structure by the propagation of the acoustic wave

         ρ: density of the medium (rock)

          C: Velocity propagation velocity of medium (rock)

          V: Vibration velocity propagated by blast shock wave

For example, assuming that a large underground cavity in which lining concrete is constructed is built in a good rock, the lining concrete has a compressive strength of 240 kgf / cm ² , a rock density of 2.5 g / cm ³ , and a rock acoustic wave speed of 3000 m / sec. The vibration tolerance of concrete is as follows.

First of all, the allowable tensile stress that a concrete structure can withstand can be obtained as follows.

Lining Concrete Tensile Strength = 24kgf / cm ² (The tensile strength of concrete is about 10% of compressive strength)

Lining concrete allowable tensile stress = 24 kgf / cm ² ÷ 3 (safety factor) = 8 kgf / cm ²

The vibration tolerance of lining concrete can be calculated to satisfy σ ≤ 8kgf / cm ² .

= 10.453cm/secV =

= 10.453 cm / sec

Lining allowance for lining concrete = 10.453cm / sec ÷ 2 (safety factor) = 5.226cm / sec

                                                                ≒ 5.0cm / sec

It is difficult to define the blasting vibration limit on the cured concrete only by the above theoretical formula.

According to the literature, the effect of blasting vibration on curing concrete is different from that of hardened concrete. In the case of hardened concrete, the existing vibration tolerance can be applied according to the type of structure.However, the cured concrete can have the design strength due to vibration, so a separate limit is applied to the concrete. .

The results of the studies up to 1970 revealed that the external vibration did not cause the decrease in strength of the cured concrete.However, the results of the studies since the 1970s indicate that the external vibration may decrease the strength over time after the concrete is poured. It is reported that it is necessary to limit the vibration level.

Based on these literatures, it is reasonable to set the vibration tolerance criteria for lining concrete under curing by time sensitive to vibrations and insensitive to strength deterioration. In the present invention, reference is made to domestic and international literatures in <Table 1>. The vibration tolerance of the cured lining concrete was divided based on 24 hours after concrete pouring.

Domestic and Overseas Institutions and Research Results Permissible Vibration Speed by Curing Time (Vibration Level Unit: cm / sec) division Curing time division Remarks
Vibration tolerance level American Society of Civil Engineers 0 to 12 hours 12 to 24 hours 1-5 days 5 days or more 0.254 1.27 1.27 to 5.08 5.08 Law Engineering Testing Company Less than 12 hours 12 hours to 7 days 7 days or more Buildings and tunnels with machines 0.25 5.1 5.1 Hulshizer & Desal, (1984) 0 to 3 hours 3 to 11 hours 11 to 24 hours 1-2 days 2 days or more 10.16 3.81 5.08 10.16 17.75 U.S. Department of Transportation (1991) 0-4 hours 4 to 24 hours 1 to 3 days 3-7 days 7-10 days 5.08 0.63 2.54 5.08 12.70 Germany 0 to 12 hours 12 to 24 hours 1-2 days 2-7 days 7-14 days 0.63 1.27 2.54 6.35 10.16 Sweden 0 to 2 days 2-3 days 3-7 days 7-28 days 28 to 90 days Curing temperature 5 ℃ 0.8 1.1 3.5 8.0 10.0 Korea Resource Research Institute
(2003) 0-4 hours 4 to 24 hours 1 to 3 days 3-7 days 7-10 days 5.08 0.63 2.54 5.08 12.70 Shin Il Jae, Lee Jung In
(1999) Less than 12 hours 2.0

In the embodiment of the present invention, the vibration tolerance standard for lining concrete specifies that curing time sensitive to vibration within 24 hours and the vibration tolerance standard is set to 0.6cm / sec. Curing time insensitive to vibration due to blasting is defined as more than 24 hours, and the vibration tolerance is determined as the value that can minimize the impact on the structure by referring to the vibration tolerance and calculated literature.

In this example, the vibration tolerance of the concrete which is insensitive to vibration is selected as 5.0cm / sec in this example, and the calculation result of the theoretical formula depends on the ground property and concrete strength. The calculation reflects the value.

Vibration Acceptance Standard of Curing Lining Concrete Curing after concrete pouring 0 to 24 hours More than 24 hours Remarks Vibration tolerance standard 0.6cm / sec 5.0 cm / sec Selection based on literature

Next, the optimum separation distance 530 of the lining concrete 510 and the excavation 520 is calculated (S120). That is, the optimum separation distance is calculated using the vibration estimation equation based on the vibration tolerance criteria selected above. At this time, since the separation distance between the lining concrete placing surface and the excavation surface may vary depending on the excavation method, the optimum separation distance is calculated by the excavation method that can reduce the vibration.

The vibration estimation equation is needed to calculate the separation distance between the lining concrete and the excavation surface. During construction, the vibration estimation formula calculated by test blasting is used in top heading and gallery blasting excavation, and in design, the separation distance is calculated by the vibration estimation formula calculated by borehole test blasting.

If the separation distance is calculated by the vibration estimation formula that is widely applied in the preliminary analysis of the tunnel before the test blast, the following can be obtained.

(K=100~200, 雜喉謙)[Equation 2]

(K = 100 ~ 200, 雜 喉 謙)

delete

Where W is less than or equal to 10 kg: n = 1

        When W is more than 10 kg: n = 0.85

        1 Free face: K = 200

        2Free face: K = 120 (extension)

        V: Vibration Speed

        D: separation distance

이 The separation distance estimated by vibration estimation Charge (W)

Distance between top heading (gallery) lining and Bench 1 digging surface (D) Apply Smooth Blasting Method Application of Line Drilling Method Vibration tolerance standard (V)
0.6cm / sec Vibration tolerance standard (V)
5.0 cm / sec Vibration tolerance standard (V)
0.6cm / sec Vibration tolerance standard (V)
5.0 cm / sec 0.5kg 12.9m 3.9 m 10.9m 3.3m

Table 3 is a result of calculating the separation distance when the Smooth Blasting method and the Line Drilling method are applied to the outermost part of Bench 1 using the vibration estimation equation. When the line drilling method is applied, it is assumed that the vibration speed is reduced by about 15 to 20%.

During actual construction, the separation distance is calculated by the vibration estimation formula calculated through the test blasting during construction, and the top heading, gallery lining, and bench 1 excavation are simultaneously installed as shown in FIG.

Next, to determine the bench 1 (Bench 1) excavation method that can improve the quality of the lining concrete (410) (S130). Select the excavation method to optimize the separation distance from the excavation surface without reducing the strength of the curing lining concrete structure.

Figure 4 In the large-scale underground cavities according to the present invention in the construction of the lining concrete placing and bench 1 (Bench 1) excavation at the same time, the bench 1 excavation divided into blasting excavation and mechanical excavation and divided by blasting excavation in two It is conceptual diagram to construct. FIG. 5 is a longitudinal sectional view of FIG. 4. FIG. 4 is a conceptual view of bench 1 showing the process of excavating bench 1 behind the optimum separation distance during the top heading, gallery lining concrete placement. .

In the excavation method of the bench 1, as shown in FIG. 4, first, a dustproof hole 420 is installed to block shock waves due to blasting on a top heading (gallery) lining concrete structure. As shown in FIG. 4, when the anti-vibration hole 420 is installed below the lining concrete 410, a vibration reduction effect may be obtained.

Next, the area of Bench 1 is divided into the mechanical excavation section 430 and the blasting excavation section at the center of both ends. Mechanical excavation to a certain distance from the lining concrete minimizes the effect of vibration on the structure.

Finally, digging is performed by dividing the center blasting excavation section of Bench 1 into two. This is to reduce the vibration due to blasting by securing a working path for the construction of the top end lining concrete 410 and reducing the amount of excavation.

In addition, various vibration reduction techniques are used in combination in order to reduce the vibration generated during the blasting excavation of Bench 1. This vibration reduction method can be used by measuring one during construction, or can be used in combination of two or three.

Figure 7 is an explanatory diagram for reducing the amount of charge per delay and excavation length used in the vibration reduction method in the present invention. As shown in the figure, the vibration reduction method for the blasting excavation may be applied to the amount of dose reduction per delay (710), the reduction of the excavation length 720, the line drilling method or the electron primer method to the outermost hole.

Next, the excavation 520 of the top heading (Gallery) lining concrete 510 and the bench 1 (Bench 1) is parallelly installed (S140). As shown in FIG. 5, the spacing calculated in step S120 and the excavation method selected in step S130 are used to improve the workability, safety, and quality by laying lining concrete at the top end and excavation of bench 1 at the bottom of the top end. Reduce construction costs

Finally, after the excavation is completed to Bench 2 (Bench 2) or Bench 3 (Bench 3), the lining concrete is poured over the entire bench, and the discarded concrete is poured on the basement floor (S150).

Figure 6 shows a process flow diagram of the construction of lining concrete in a large-scale underground cavity according to the present invention.

As shown in the figure, after lining and reinforcing the tip ends, the lining concrete is poured. In the above process, excavation for the bench 1 section is performed in parallel. The bench 1 excavation is divided into two times and the blasting excavation is performed, followed by mechanical excavation. When the excavation of the bench 1 is completed, reinforcement is performed, and the excavation and reinforcement of the bench 2 are performed to the bottom of the bench 1 as the next step. Finally, lining concrete for bench 1 and benches 2 and 3 is poured.

The present invention described above is not limited to the above-described embodiment and the accompanying drawings, and various substitutions, modifications, and changes are possible within the scope without departing from the technical spirit of the present invention. It will be apparent to those who have knowledge.

210, 220: large-scale underground cavities 410: lining concrete
420: anti-vibration 430: machine excavation section
510: end of the lining concrete 520: bench 1 excavation
530: optimal separation distance 710: reduction of charge per delay
720: shrink the excavation site

Claims (5)

delete delete A first step of setting the lining concrete vibration tolerance standard of the top end according to the excavation of the bench 1 (Bench 1) of the large basement underground after excavation and reinforcement of the top heading or gallery in the large underground cavity;
A second step of calculating an optimum separation distance between the lining concrete and the excavation;
A third step of simultaneously constructing the excavation of the bench 1 at the lower end of the position away from the end of the ceiling by the spacing calculated with the lining concrete construction of the ceiling; And
Fourth step of pouring lining concrete for the entire bench (Bench) after the excavation of the bench 2 (Bench 2) and bench 3 (Bench 3) at the bottom of the bench 1
Including but not limited to:
The lining concrete vibration tolerance standard of the first step is as follows.
[Equation 1]
σ = ρ CV
Where σ is the stress applied to the concrete structure by the propagation of the acoustic wave
ρ: density of the medium (rock)
C: Velocity propagation velocity of medium (rock)
V: Vibration velocity propagated by blast shock wave
Vibration allowance of lining concrete = V ÷ Safety factor
The vibration tolerance is set by dividing it into less than 24 hours and more than 24 hours according to the curing degree of lining concrete.
The second step is
During the construction, the vibration estimation equation calculated by the test blasting is used in the blasting excavation of the top end, and the designing distance is calculated using the vibration estimation formula calculated by the borehole test blasting.
[Equation 2]

(K = 100 ~ 200, 雜 喉 謙)
Where W is less than or equal to 10 kg: n = 1
When W is more than 10 kg: n = 0.85
1 Free face: K = 200
2Free face: K = 120 (extension)
V: Vibration Speed
D: separation distance
Construction method for lining concrete in large-scale underground cavities, characterized in that calculated on the basis of.
The method of claim 3, wherein
In the third step,
A method of constructing lining concrete in a large underground cavity, including installing a dustproof under the lining concrete to block shock waves caused by blasting on the lining concrete structure of the top end.
The method of claim 3, wherein
The third step includes a first process of dividing the area of the bench 1 into a mechanical excavation section on both sides of the top end and a center blasting section;
A second process of blasting and dividing the bench 1 blasting section into two spaced distances from the lining concrete of the top end; And
Third process for carrying out mechanical excavation of the bench 1
Lining concrete construction method in a large underground cavities including.

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