KR102181396B1 - Reinforcing method of pre-drilling before tunnel excavation and tunnel excavation method using the same - Google Patents

Abstract

The present invention relates to a reinforcement method for pre-perforating a tunnel before tunnel excavation and a tunnel excavation method using the same, wherein the reinforcement method for pre-perforating a tunnel before tunnel excavation installs surface reinforcement materials by pre-perforating the outside of a tunnel excavation surface in a state of the original ground before tunnel excavation. The reinforcement method for pre-perforating a tunnel before tunnel excavation constructs the surface reinforcement materials in a structure in which a standard of the surface reinforcement materials is reduced toward the inside of perforation holes while a plurality of surface reinforcement materials are expanded in a telescopic type, or effectively reinforces the inside of the perforation holes and the outside of the perforation holes by pressurization grouting after the reinforcement materials are installed in accordance with properties of the ground by additional reinforcement on the inside or the outside of the reinforcement materials having the certain standard, thereby improving straightness of the surface reinforcement materials, reducing an installation cost, reducing a land purchase and forest damage, and shortening a construction period. To this end, the reinforcement method for pre-perforating a tunnel before tunnel excavation comprises a stratum scanning step (S10), a first perforation hole forming step (S20), a first surface reinforcement material constructing step (S30), a second perforation hole forming step (S40), a second surface reinforcement material constructing step (S50), a third perforation hole forming step (S60), and a third surface reinforcement material constructing step (S70).

Description

Reinforcing method of pre-drilling before tunnel excavation and tunnel excavation method using the same}

The present invention relates to a pre-drilling reinforcement method before tunnel excavation and a tunnel excavation method using the same, and more particularly, by pre-drilling the outside of the tunnel excavation surface in the original ground state before tunnel excavation to install an external reinforcement material, As the reinforcing material is expanded to a telescopic type, the size of the external reinforcement material is reduced as it goes into the perforated hole, and the external reinforcement is constructed, or a reinforcement is installed in accordance with the characteristics of the ground by additional reinforcement inside or outside the reinforcement of a certain standard, and then punched with pressure grouting. A pre-drilling reinforcement method before tunnel excavation and a tunnel excavation method using the same, which can effectively reinforce the inside of the hole and the ground outside the perforated hole to improve the straightness of the reinforcement material outside the mine and reduce the installation cost, reduce land purchase and forest damage, and shorten the construction period. It is about.

In general, in order to excavate the tunnel safely in tunnel construction, the soft original ground is cut to a certain depth, and then an external reinforcement is installed on the intended tunnel line in a good rock condition to secure stability and excavate the tunnel. That is, in order to expose to good ground, a large area above the tunnel entrance must be cut with a certain slope and the upper surface of the tunnel must be stably reinforced.

As such, due to the cutting of the original ground, a large amount of slope reinforcement has to be constructed to secure the stability of the slope made on the tunnel shaft, and the land compensation area increases along with damage to the natural environment.

Due to this problem, recently, after cutting the original ground to a minimum, the size of the reinforcement outside the mine was increased at the top of the tunnel planned excavation line, and the size of the reinforcement was increased by the distance of the original ground, so that the reinforcement of large-diameter steel pipes (126m/m~300m/m) to a certain standard I am installing.

It is used as a so-called pipe loop construction method, but when the original ground is cut to a minimum, the size of the external reinforcement material must be very large because the remaining original ground is soft. In addition, the external reinforcement material that must be reinforced when the original ground is removed and tunnels of good ground are constructed. Since reinforcement is required to the distance at once, the length of the reinforcement outside the shaft becomes very long.

In this way, when the size of the reinforcing material increases and the length of the reinforcement material becomes longer, the hole diameter to insert the reinforcement material becomes larger, and when drilling with a larger hole diameter, the drilling speed is very slow, so the construction time for drilling takes a very long time. In addition, when the perforation length becomes longer, the straightness of the perforation decreases and construction precision is deteriorated.

In addition, because the size of the reinforcing material is large, the cost is high, and the workability is poor due to the large weight of the reinforcing material. It is difficult to maintain the straightness due to the change, so it is very difficult to insert and install a reinforcing material in a single line.In particular, as the rod portion of the perforator becomes longer, the sag width increases and the power transmission efficiency to the head of the perforator decreases.

KR 10-1580961 B1 (2015.12.22.) KR 10-1665515 B1 (2016.10.16.)

Accordingly, the present invention was conceived in order to solve the above problems, and by pre-drilling the outside of the tunnel excavation surface in the original ground state before tunnel drilling to install an external reinforcement, a plurality of external reinforcements were expanded into a telescopic type and drilled. It is a structure in which the size of the stiffener outside the pit is reduced as it goes inside the hole.Or, after installing a stiffener according to the characteristics of the ground as additional reinforcement inside or outside the stiffener of a certain standard, pressurized grouting to the inside of the hole and the ground outside the hole. Its purpose is to provide a pre-drilling reinforcement method before tunnel excavation and a tunnel excavation method using the same, which can effectively reinforce and improve the straightness of the reinforcement material outside the pit and reduce the installation cost, reduce land purchase and forest damage, and shorten the construction period. .

In order to achieve this object, a feature of the present invention is the stratum scanning step (S10) of detecting the thickness of each stratum in the tunnel progress direction outside the tunnel excavation surface corresponding to the shaft of the tunnel 10; A plurality of first perforated holes 20 are formed at an angle of 6° or less based on the direction of tunnel progress outside the predetermined tunnel excavation surface at the entrance of the tunnel 10, and the first perforated hole 20 is expanded compared to the thickness of the surface layer. The first perforated hole forming step (S20) formed to the depth; A first off-pit reinforcement construction step (S30) of reinforcing the surface stratum (1) by inserting the first out-of-pit reinforcement material 30 into the first perforated hole 20; By inserting a perforated rod into the inner space of the first off-pit reinforcement 30 to form a second perforated hole 40 with a reduced diameter compared to the first perforated hole 20, the second perforated hole 40 is an intermediate layer ( 2) forming a second perforated hole perforated to an extended depth compared to the thickness (S40); The second off-pit reinforcement 50 is inserted into the second perforated hole 40 through the inner space of the first off-pit reinforcement 30 to reinforce the intermediate stratum 2, and the second off-pit reinforcement 50 and the first It characterized in that it comprises a; a second out-of-pit reinforcement construction step (S50) of constructing such that the first overlapping portion 52 is formed in which the ends of the out-of-pit reinforcement 30 are engaged.

At this time, by inserting a perforation rod into the inner space of the first and second reinforcement materials 30 and 50 to form a third perforated hole 60 having a reduced diameter compared to the second perforated hole 40, and a third perforated hole 60 is a third perforated hole forming step (S60) which is perforated to extend into the inner stratum 3; And inserting a third external reinforcement material 70 into the third perforated hole 60 through the internal space of the first and second external reinforcements 30 and 50 to reinforce the internal stratum 3, and the third external reinforcement It characterized in that it comprises a; (70) and the second out-of-pit reinforcement 50, a third out-of-pit reinforcement construction step (S70) of constructing such that the second overlapping portion 72 is formed in engagement with the end.

In addition, the rear end of the first pit reinforcement 30 is inserted deeper than the first puncture hole 20, and the first puncture hole 20 between the inlet of the first pit 20 and the rear end of the first pit stiffener 30 ) The filling material 22 is poured in the section, and the filling material 22 is provided to be removed when cutting the shaft of the tunnel 10.

In addition, an auxiliary reinforcement 81 is inserted into any one or more of the first, second, and third off-pit reinforcements 30, 50, and 70, or the internal reinforcement 80 from the inside of the tunnel 10 excavation surface to the outside. It is characterized in that it is provided so as to overlap with any one of the first, second, and third off-pit reinforcements 30, 50, and 70 for a predetermined period.

In addition, after the construction of the first and second off-pit reinforcements 30 and 50 or the third off-pit reinforcement 70, a part of the entrance of the tunnel 10 is excavated, and the first from the inside of the tunnel 10 excavation surface to the outside. , 2, 3 The pit reinforcement 80 is constructed at 8 to 25° to pass through the 2nd and 3rd off-pit stiffeners 30, 50, and 70, and the rear end of the pit stiffener 80 is a support material to be installed near the planned tunnel excavation line ( It is located between the support member 82 and the support member 82, and passes the upper portion of the neighboring support member 82, and the reinforcing member 80 is repeated at regular intervals.

In addition, when the shaft portion of the tunnel 10 is cut and excavated, the trailing end of the first out-of-pit reinforcement material 30 is exposed to the outside of the first perforated hole 20 to form an extension part 32, and a first A plurality of through-holes 33 perpendicular to the longitudinal direction of the off-pit reinforcement 30 are formed, and a fixing pin 33a is inserted and installed in the through-hole 33, and corresponding to the entrance of the first perforated hole 20 The inner and outer spaces at the ends of the first outside reinforcement 30 are closed by inner and outer caulking agents 24 and 24', and the inner and outer caulking agents 24 and 24' are attached to the fixing pins 33a. It characterized in that it is provided so as to prevent push in the outward direction.

In addition, the bulkhead block 90 is inserted into at least one of the first and second off-pit reinforcements 30 and 50, so that the outer circumferential surface is in close contact with the inner circumferential surface of the off-pit reinforcement, and a guide hole 92 is formed in the center. It is provided, and the partition wall block 90 is characterized in that it is provided to rotatably support the perforated rod (R).

In addition, a plurality of grout holes 31, 51 and 71 are formed on the outer circumferential surface of the first, second, and third off-pit reinforcements 30, 50, and 70, and the first, second, and third off-pit reinforcements 30 ) (50) (70) It is provided to simultaneously pressurize the inside and outside of the 1st, 2nd, 3rd shaft reinforcement material 30, 50, 70 by injecting grout filler with the grout hose (G) inserted into the interior. It is characterized by being.

In addition, a hole filling material 84 is installed between the rear end of the pit reinforcement 80 and the entrance of the hole where the pit reinforcement 80 is installed, and the hole filling material 84 is provided to be removed during tunnel excavation.

In addition, pressure grouting is performed by being inserted into the grout hose (G) and the air blowing hose (A) into the reinforcements 30, 50, 70 outside the first, second, and third shafts, and the grout hose (G) A plurality of through-holes (G1) are formed at regular intervals with the tip closed, the grouting filler injection pump (P) is connected to the rear part, and the air ejection hose (A) is penetrated through both ends. Is disposed near the front end of the third off-pit reinforcement material (70), and the tail is exposed to the outside of the first off-pit reinforcement material (30) to discharge the first, second, and third off-pit reinforcements (30, 50, 70) It is characterized by being.

In addition, the grout hose (G) has a trailing portion extending outside the first gangway reinforcement (30) to form two injection pipes (G3) by a Y-shaped pipe (G2), and a pump (P) in each injection pipe. It is connected to, and characterized in that it is provided so that the grouting filler is injected by each pump (P).

In addition, an expansion material 34 is installed between the rear end of the first off-pit reinforcement material 30 and the entrance of the perforated hole, between the rear end of the tunnel reinforcement material 80 and the entrance of the perforation hole, and a through hole 34a is formed in the expansion material 34 It characterized in that the grout hose (G) and the air jet hose (A) is provided to be inserted through.

In addition, a guide pipe (G4) is installed to guide the entry of the grout hose (G) by being installed at the rear of the first external reinforcement 30 or the rear of the internal reinforcement 80, and the guide pipe G4 is a grout hose (G). It is characterized in that it is provided to be removed after the insertion is completed or when the tunnel 10 is excavated.

In addition, the guide pipe (G4) is formed of the same material as the external reinforcement material and the internal reinforcement material 80, or is formed of any one of a PVC pipe and a geosynthetic pipe, and the guide pipe (G4) is a first external reinforcement material (30) and the reinforcing material 80 in the pit are integrally connected to the rear or installed detachably, and an elastic member (G5) is attached to the outside of the guide tube (G4), and may be provided to caulk between the perforated holes. do.

In addition, a plurality of first compartments (30a) are spaced apart from the inside of the first off-pit stiffener 30 to form a plurality of first compartments (30a) inside the first off-pit reinforcement (30), and a first guide hole (94a) is formed in the center. A first partition wall block 94 is provided, and is spaced apart from the inside of the second off-pit reinforcement 50 to form a plurality of second compartments 50a inside the second off-pit reinforcement 50, and a second guide at the center A plurality of second partition wall blocks 96 in which holes 96a are formed are provided, and a grout hose G is provided to be inserted through the first and second guide holes 94a and 96a, and the plurality of The end of the second guide hole 96a of the second partition wall block 96 disposed in the front of the second partition wall block 96 is formed with a locking protrusion 96b so that the end of the grout hose G is engaged and bound. The first partition wall block 94 and the second partition wall block 96 are bound to each other by a traction rope 97, and a backslip prevention means 98 on the outer circumferential surface of the first partition wall block 94 and the second partition wall block 96 It is installed so that the first and second reinforcement members 30 and 50 are allowed to move in the inward direction and are provided to limit the outward movement,

Before inserting the grout hose (G) into the first and second off-pit reinforcements (30) (50), the grout hose (G) is inserted into the grout hose (G) through the first and second guide holes (94a) (96a). When a plurality of first and second partition wall blocks 94 and 96 are inserted, and the grout hose G is inserted into the first and second off-pit reinforcement members 30 and 50, the end of the grout hose G Among the second bulkhead blocks 96, the second bulkhead blocks 96 that are disposed in front of the second bulkhead blocks 96 are hooked and bound to the first and second pit reinforcements 30 and 50 together with the grout hose G. As it moves, the adjacent first and second partition wall blocks 94 and 96 are inserted by the traction rope 97 while maintaining a predetermined distance, and when the grout hose G reaches a predetermined depth, the grout filler Is supplied and a grout filler is filled into the inside of the front second compartment 50a formed by the second bulkhead block 96 disposed in front of the plurality of second bulkhead blocks 96, and the internal pressure of the second compartment 50a When this rises, the second partition wall block 96 is prevented from being pushed by the backslip preventing means, and the grout filler is charged at high pressure, and then the grout hose G is placed at the distance between the second partition wall block 96 and the first partition wall block ( 94) is intermittently withdrawn as much as the distance between each of the first and second compartments (30a, 30b) is provided to fill the grout filler step by step, and the grout to be filled for each of the first and second compartments (30a) (30b) The first, second, and third off-pit reinforcement materials 30 through a plurality of grout holes 31, 51 and 71 formed on the outer circumferential surface of the first, second, and third off-pit reinforcement materials 30 by the filler pressure. ) (50, 70) characterized in that it is provided to grout the grout filler to the outer region.

In addition, the back-slip prevention means 98 has an inclined rail groove 98a extending to the rear end of the first out-of-pit reinforcement 30 on the outer circumferential surfaces of the first and second partition wall blocks 94 and 96, and the inclined rail groove ( 98a) is formed at a downward inclination angle toward the center of the first and second bulkhead blocks 94 and 96 toward the rear end of the first off-pit reinforcement 30, and a stop ball 98b is inserted into the inclined rail groove 98a to cover It is installed to be partially exposed to the outside by (98c), and when the first and second bulkhead blocks 94 and 96 move in the first and second pit reinforcements 30 and 50 in the inward direction, the stop ball 98b is inclined rail By moving to the deep end of the groove 98a, friction with the first and second partition wall blocks 94 and 96 is prevented, and the first and second partition wall blocks 94 and 96 reinforce the first and second shafts ( 30) (50) When moving in the outward direction, the stop ball (98b) moves to the shallow end of the inclined rail groove (98a) and is pinched in a state of friction with the first and second bulkhead blocks (94, 96),

The backslip prevention means 98 has one end connected to the outer circumferential surface of the first and second partition wall blocks 94, 96, and the other end at an outward inclination angle toward the outside of the first and second off-pit reinforcements 30, 50. It is formed of the formed stop piece (98d). Accordingly, when the first and second bulkhead blocks 94 and 96 move in the first and second pit reinforcements 30, 50, the first and second bulkhead blocks 94 and 96 are folded with the stop piece 98d folded. When the first and second bulkhead blocks 94 and 96 move outwardly, the first and second bulkhead blocks 94 and 96 are moved outwardly, and the first and second bulkhead blocks ( It is characterized in that it is provided so as to be pinched in a state of friction with the 94) (96) and fixed in position.

In addition, in drilling the first perforated hole 20, the second perforated hole 40, and the third perforated hole 60, a direct perforating method is used, and the first perforated hole 20 or the second perforated hole ( 40) It is characterized in that a recovery bit is used during construction.

In addition, the adjacent installation intervals of the stiffeners 30, 50, 70 and the stiffeners 80 installed around the tunnel are wide in the front end and narrow in the sidewall, or the installation interval is constant and the sidewall It characterized in that the auxiliary stiffener 81 is installed inside the reinforcement.

In addition, after installing the first, second, and third outboard reinforcements with the same standard, auxiliary reinforcement is additionally installed inside the outboard reinforcement for a certain section according to the ground characteristics, or an internal reinforcement is installed so as to overlap with the outboard reinforcement. .

The tunnel excavation method using the pre-drilling reinforcement method before tunnel excavation according to the present invention comprises: a) forming a perforated hole at regular intervals on the upper part of the tunnel 10, and the first, second, and third reinforcement materials 30 )(50)(70) are installed, caulking between the hole inlet and the rear end of the first gangway reinforcement (30), and then the first, second, and third gangway reinforcements (30) (50) (70) inside and outside Grouting to the ground outside the perforated hole by pressing grouting (S100); b) curing the grout of the first, second, and third off-pit reinforcements 30, 50, and 70, and installing the shaft door 200 (S200); c) Excavating the tunnel 10 to a certain distance and repeating the installation of the support material 82 and the pouring of the shotcrete 83 (S300); d) A perforated hole is formed from the inside of the tunnel 10 to the outside, and an intra-pit reinforcement 80 is installed inside the perforated hole, and the rear end of the inner reinforcement 80 is located near the excavation surface of the tunnel 10. After finishing the hole filling material 84 between the rear end of the reinforcing material 80 and the inlet of the perforated hole, pressure grouting to the inside, outside and the ground around the perforated hole in the reinforcing material 80 in the pit (S400); And e) tunnel reinforcement 80 to a position where the rear end of the pit reinforcement 80 is not exposed without waiting time for grout curing when the pressurized grout filler has fluidity or chemical reaction is in progress, and the support material 82 And the step of pouring the shotcrete 83 (S500); and repeating steps c) to e).

According to the above configuration and operation, the present invention pre-drills the outside of the tunnel excavation surface in the original ground state before the tunnel excavation to install an out-of-pit reinforcement, so that a plurality of out-of-pit reinforcements are expanded in a telescopic type so as to go into the perforated hole. Reinforcement is installed outside the pit with a structure with a reduced size, or reinforcement is installed in accordance with the characteristics of the ground by additional reinforcement inside or outside the stiffener of a certain standard, and then effectively reinforced to the inside of the hole and the ground outside the hole with pressure grouting. It has the effect of shortening the construction period while improving straightness and reducing installation costs, reducing land purchase and forest damage.

1 is a block diagram schematically showing a method for reinforcing pre-drilling before tunnel excavation according to an embodiment of the present invention.
2 is a block diagram schematically showing a tunnel excavation method using a pre-drilling reinforcement method before tunnel excavation according to an embodiment of the present invention.
3 is a conceptual diagram of a method for reinforcing pre-drilling before tunnel excavation according to the present invention.
4 is a configuration diagram showing another installation example of the present invention.
5 is an exemplary view of adding an auxiliary stiffener inside the reinforcement outside the shaft of the present invention (installation of the auxiliary stiffener inside the stiffener)
Figure 6 is an example diagram showing the anti-skid system of the present invention.
Figure 7 is an exemplary view of the installation of the reinforcement material and the reinforcement outside the shaft of the present invention.
Figure 8 is an exemplary view showing the installation of the barrier film at the rear of the reinforcement material in the pit of the present invention and the installation of the filling material between the barrier film from the entrance of the hole.
FIG. 9 is another exemplary view of the present invention, which allows simultaneous pressure grouting with an air jet hose and one grout hose.
Figure 10 is an example of the rod sag prevention and head sagging prevention diagram of the present invention
11 is an exemplary view of installing an inflatable material using the induction device of the present invention
12 is a view showing a grout hose installation using the guide tube of the present invention.
13 to 17 are construction flow charts according to the method of reinforcing drilling before tunnel excavation of the present invention and a tunnel excavation method using the same.
18 to 19 are configuration diagrams showing a grout method using a partition wall block of a method for reinforcing pre-drilling before tunnel excavation according to an embodiment of the present invention.
Fig. 20 is a configuration diagram showing a state of soil in the original ground.
Fig. 21 is a configuration diagram showing an installation cross-sectional view of an existing construction method.
Figure 22 is an installation cross-sectional view of the existing construction method (large-diameter pipe loop construction method)
23 is a block diagram showing the arrangement state of the reinforcement outside the tunnel of the pre-drilling reinforcement method before tunnel excavation according to an embodiment of the present invention.

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

The present invention proposes a new method to save construction time and construction cost while being an efficient construction method by varying the standard or method step by step in installing the reinforcement before tunnel excavation, and to achieve a stable construction during tunnel excavation.

Specifically, to reduce forest damage by maintaining the original ground condition of the shaft before tunnel excavation as much as possible, reduce the amount of reinforcement on the top of the shaft and the cost of purchasing land around the shaft, while installing reinforcing materials with high standards or rigidity in the weak ground. In addition, a method of reinforcing a perforation before excavation of a tunnel that secures the stability of the tunnel and improves the workability and economy by reinforcing the standard or method differently according to the strength of the ground in which small dimensions and reinforcement materials with low rigidity are installed in the strong ground. Suggest.

FIG. 20 is a diagram showing the soil state of the original ground consisting of the surface stratum (soil layer), the intermediate stratum (weathered rock), and the inner stratum (soft rock layer), and is a representative cross-sectional view of the ground on which tunnel construction is performed.

FIG. 21 is a view showing a conventional tunnel excavation starting point and the installation of an off-pit reinforcement on the shaft in the ground state as shown in FIG. 20. The shaft is located near the weathered rock where the soft soil is cut in the original ground state and the shear strength is maintained to some extent. It is a drawing to form.

In this way, when a shaft is formed by cutting a lot of original ground, a lot of cut slopes are generated at the top of the shaft, resulting in a large amount of slope reinforcement, forest damage, and land purchase costs.

However, before the tunnel excavation at this time, the external reinforcement is installed with a slightly smaller size.

Due to this problem, in recent years, in a state in which the upper cut-off of the shaft portion is reduced as much as possible in the manner shown in FIG. 22, an external reinforcement material using a reinforcing material having a predetermined standard is installed before tunnel excavation.

As shown in Fig. 22, the construction time is very long and construction costs are very high because the external reinforcement material from the shaft part up to 300 m/m of the large standard is installed by extending it to the line unit value of the external reinforcement material in Fig. 21 with the same uniform standard. However, it is not possible to install an efficient reinforcement according to the ground conditions.

In addition, installation is possible only in a direct drilling method in which a reinforcing material is installed together with drilling.

Accordingly, the present invention is a construction method of adding an auxiliary reinforcement material to a location inside the external reinforcement material or adding an internal reinforcement material before excavation in the tunnel according to the ground condition, giving a difference by varying the specifications of the soil, weathered rock, and soft rock. A method of efficiently reinforcing each stratum in a stratum made of such as will be described below with reference to the drawings.

The present invention relates to a pre-drilling reinforcement method before tunnel excavation and a tunnel excavation method using the same, which is to install an external reinforcement material by drilling the outside of the tunnel excavation surface in the original ground state before the tunnel excavation, and a plurality of external reinforcement materials are telescopic. It is a structure that expands to the type and reduces the size of the stiffener outside the pit as it goes into the hole, or installs a stiffener according to the ground characteristics by additional reinforcement inside or outside the stiffener of a certain standard, and then pressurized grouting The stratum scan step (S10) and the first drilled hole formation step (S20) so that the construction period can be shortened while effectively reinforcing the ground outside the perforated hole to improve the straightness of the reinforcement and reduce installation costs, and to reduce the purchase of land and forest damage. , The first off-pit reinforcement construction step (S30), the second drilling hole formation step (S40), the second off-pit reinforcement construction step (S50), the third drilling hole formation step (S60), the third off-pit reinforcement construction step (S70) Is the main composition. The stratum scanning step (S10) may be confirmed by horizontal boring at the entrance of the tunnel, or the contents confirmed by the ground survey may be replaced with those described in the design document.

The pre-drilling reinforcement method before tunnel excavation according to the present invention includes a stratum scanning step (S10) of detecting the thickness of each stratum in the direction of the tunnel traveling outside the tunnel excavation surface corresponding to the shaft part of the tunnel 10, and the entrance of the tunnel 10 A plurality of first perforated holes 20 are formed at an angle of 6° or less based on the direction of the tunnel outside the predetermined tunnel excavation surface, and the first perforated holes 20 are formed at an extended depth compared to the thickness of the surface layer. A first drilling hole forming step (S20), and a first off-pit reinforcement construction step (S30) of reinforcing the surface stratum 1 by inserting and constructing the first pit reinforcement material 30 into the first puncture hole 20, and , By inserting a perforated rod into the inner space of the first off-pit reinforcement 30 to form a second perforated hole 40 with a diameter reduced compared to the first perforated hole 20, the second perforated hole 40 is an intermediate stratum (2) The step of forming a second perforated hole (S40) that is perforated to an extended depth compared to the thickness, and a second outer reinforcement 50 into the second perforated hole 40 through the inner space of the first off-pit reinforcement material 30 The second out-of-pit reinforcement construction step of reinforcing the intermediate stratum 2 by inserting and constructing the first overlapping portion 52 in which the ends of the second out-of-pit reinforcement 50 and the first out-of-pit reinforcement 30 are formed ( S50).

At this time, by inserting a perforation rod into the inner space of the first and second reinforcement materials 30 and 50 to form a third perforated hole 60 having a reduced diameter compared to the second perforated hole 40, and a third perforated hole 60 is a third perforated hole forming step (S60) which is perforated to extend into the inner stratum 3 and the third perforated hole 60 through the inner space of the first and second reinforcement members 30 and 50 Reinforce the inner strata (3) by inserting the 3rd out-of-pit reinforcement material (70), and construct a second overlapping part (72) where the ends of the third out-of-pit reinforcement material (70) and the second out-of-pit reinforcement material (50) are formed. It includes a third off-pit reinforcement construction step (S70).

In addition, the rear end of the first pit reinforcement 30 is inserted deeper than the first puncture hole 20, and the first puncture hole 20 between the inlet of the first pit 20 and the rear end of the first pit stiffener 30 ) The filling material 22 is poured in the section, and the filling material 22 is provided to be removed when the shaft of the tunnel 10 is cut and excavated.

In a general case as shown in Fig. 23 (a), the adjacent reinforcing material spacing is uniformly installed. However, the force that the reinforcement resists when excavating a tunnel is small at the top and large at the side walls. Accordingly, as shown in FIGS. 23(b) and 23(c), the spacing of the sidewall portions may be narrower than that of the top portion, or internal reinforcement may be installed on the sidewall portions to increase resistance.

In addition, an auxiliary reinforcement 81 is inserted into any one or more of the first, second, and third off-pit reinforcements 30, 50, and 70, or the internal reinforcement 80 from the inside of the tunnel 10 excavation surface to the outside. It is provided so as to overlap with any one of the first, second, and third off-pit reinforcements 30, 50, and 70.

In addition, after the construction of the first and second off-pit reinforcements 30 and 50 or the third off-pit reinforcement 70, a part of the entrance of the tunnel 10 is excavated, and the first from the inside of the tunnel 10 excavation surface to the outside. , 2, 3 The pit reinforcement 80 is constructed at 8 to 25° to pass through the 2nd and 3rd off-pit stiffeners 30, 50, and 70, and the rear end of the pit stiffener 80 is a support material to be installed near the planned tunnel excavation line ( It is disposed between the support member 82 and the support member 82 and is provided so as to pass through the upper portion of the neighboring support member 82.

In addition, when the shaft portion of the tunnel 10 is cut and excavated, the trailing end of the first out-of-pit reinforcement material 30 is exposed to the outside of the first perforated hole 20 to form an extension part 32, and a first A plurality of through-holes 33 perpendicular to the longitudinal direction of the off-pit reinforcement 30 are formed, and a fixing pin 33a is inserted and installed in the through-hole 33, and corresponding to the entrance of the first perforated hole 20 The inner and outer spaces at the ends of the first outside reinforcement 30 are closed by inner and outer caulking agents 24 and 24', and the inner and outer caulking agents 24 and 24' are attached to the fixing pins 33a. It is provided so as to prevent it from being pushed outward.

In addition, the bulkhead block 90 is inserted into at least one of the first and second off-pit reinforcements 30 and 50, so that the outer circumferential surface is in close contact with the inner circumferential surface of the off-pit reinforcement, and a guide hole 92 is formed in the center. It is provided, and the partition wall block 90 is provided to rotatably support the perforated rod R.

In addition, a plurality of grout holes 31, 51 and 71 are formed on the outer circumferential surface of the first, second, and third off-pit reinforcements 30, 50, and 70, and the first, second, and third off-pit reinforcements 30 ) (50) (70) It is provided to simultaneously pressurize the inside and outside of the 1st, 2nd, 3rd shaft reinforcement material 30, 50, 70 by injecting grout filler with the grout hose (G) inserted into the interior. do.

In addition, a hole filling material 84 is installed between the rear end of the pit reinforcement 80 and the entrance of the hole where the pit reinforcement 80 is installed, and the hole filling material 84 is provided to be removed during tunnel excavation.

In addition, pressure grouting is performed by being inserted into the grout hose (G) and the air blowing hose (A) into the reinforcements 30, 50, 70 outside the first, second, and third shafts, and the grout hose (G) A plurality of through-holes (G1) are formed at regular intervals with the tip closed, the grouting filler injection pump (P) is connected to the rear part, and the air ejection hose (A) is penetrated through both ends. Is disposed near the front end of the third off-pit reinforcement material (70), and the tail is exposed to the outside of the first off-pit reinforcement material (30) to discharge the first, second, and third off-pit reinforcements (30, 50, 70) do.

In addition, the grout hose (G) has a trailing portion extending outside the first gangway reinforcement (30) to form two injection pipes (G3) by a Y-shaped pipe (G2), and a pump (P) in each injection pipe. It is connected to, and is provided so that the grouting filler is injected by each pump (P).

In addition, an expansion material 34 is installed between the rear end of the first off-pit reinforcement material 30 and the entrance of the perforated hole, between the rear end of the tunnel reinforcement material 80 and the entrance of the perforation hole, and a through hole 34a is formed in the expansion material 34 It is provided so that the grout hose (G) and the air jet hose (A) are inserted through.

In addition, a guide pipe (G4) is installed to guide the entry of the grout hose (G) by being installed at the rear of the first external reinforcement 30 or the rear of the internal reinforcement 80, and the guide pipe G4 is a grout hose (G). It is provided to be removed after the insertion is completed or when the tunnel 10 is excavated.

In addition, the guide pipe (G4) is formed of the same material as the external reinforcement material and the internal reinforcement material 80, or is formed of any one of a PVC pipe and a geosynthetic pipe, and the guide pipe (G4) is a first external reinforcement material 30 and the reinforcing member 80 in the pit are integrally connected to the rear or installed detachably, and an elastic member G5 is attached to the outside of the guide pipe G4 to caulk between the perforated holes.

In addition, a plurality of first compartments (30a) are spaced apart from the inside of the first off-pit stiffener 30 to form a plurality of first compartments (30a) inside the first off-pit reinforcement (30), and a first guide hole (94a) is formed in the center. A first partition wall block 94 is provided, and is spaced apart from the inside of the second off-pit reinforcement 50 to form a plurality of second compartments 50a inside the second off-pit reinforcement 50, and a second guide at the center A plurality of second partition wall blocks 96 in which holes 96a are formed are provided, and a grout hose G is provided to be inserted through the first and second guide holes 94a and 96a, and the plurality of The end of the second guide hole 96a of the second partition wall block 96 disposed in the front of the second partition wall block 96 is formed with a locking protrusion 96b so that the end of the grout hose G is engaged and bound. The first partition wall block 94 and the second partition wall block 96 are bound to each other by a traction rope 97, and a backslip prevention means 98 on the outer circumferential surface of the first partition wall block 94 and the second partition wall block 96 This is installed so that the first and second reinforcement members 30 and 50 are allowed to move in the inward direction and the outward movement is limited.

Here, the back-slip prevention means 98 has an inclined rail groove 98a extending to the rear end of the first and second bulkhead blocks 94 and 96 on the outer circumferential surfaces of the first and second bulkhead blocks 94, 96, and the inclined rail groove ( 98a) is formed at a downward inclination angle toward the center of the first and second bulkhead blocks 94 and 96 toward the rear end of the first off-pit reinforcement 30, and a stop ball 98b is inserted into the inclined rail groove 98a to cover It is installed to be partially exposed to the outside by (98c).

Accordingly, when the first and second partition wall blocks 94 and 96 move in the inner direction of the first and second pit reinforcements 30, 50, the stop ball 98b moves to the deep end of the inclined rail groove 98a, , The friction with the second partition wall blocks 94 and 96 is prevented, and the first and second partition wall blocks 94 and 96 move outward when the first and second reinforcement members 30 and 50 are moved outward, and the stop ball 98b It moves to the shallow end of the inclined rail groove 98a and is pinched in a state of friction with the first and second partition wall blocks 94 and 96, and the position is fixed.

In addition, the back slip prevention means 98 has one end connected to the outer circumferential surface of the first and second partition wall blocks 94, 96, and the other end of the first and second outer pit reinforcement members 30, 50 toward the outside. It is formed with a stop piece (98d) formed at an inclination angle. Accordingly, when the first and second bulkhead blocks 94 and 96 move in the first and second pit reinforcements 30, 50, the first and second bulkhead blocks 94 and 96 are folded with the stop piece 98d folded. When the first and second bulkhead blocks 94 and 96 move outwardly, the first and second bulkhead blocks 94 and 96 are moved outwardly, and the first and second bulkhead blocks ( 94) It is pinched in a state of friction with (96) and fixed in position.

And before inserting the grout hose (G) into the first and second off-pit reinforcements 30, 50, the grout hose (G) through the first and second guide holes (94a) (96a) through the grout hose (G). When a plurality of first and second bulkhead blocks 94 and 96 are inserted into the wall and the grout hose G is inserted into the first and second reinforcement materials 30 and 50, the end of the grout hose G Among the second bulkhead blocks 96 of the first and second pit reinforcements 30 and 50 are engaged with the hooking protrusions 96b of the second bulkhead blocks 96 disposed in the front and together with the grout hose G. While moving to, the adjacent first and second partition wall blocks 94 and 96 are inserted by the traction rope 97 while maintaining a predetermined distance.

When the grout hose (G) reaches a predetermined depth, a grout filler is supplied to the front second compartment 50a formed by the second bulkhead block 96 disposed in front of the plurality of second bulkhead blocks 96 ) When the internal pressure of the second compartment 50a increases due to the filling of the grout filler, the second bulkhead block 96 is prevented from being pushed by the backslip prevention means, and the grout filler is charged at high pressure, and then the grout hose (G) Is intermittently drawn out as much as the distance between the second partition wall blocks 96 and the distance between the first partition wall blocks 94, and is provided to fill the grout filler step by step for each of the first and second compartments 30a and 30b.

At this time, a plurality of grout holes 31 formed on the outer circumferential surfaces of the first, second, and third pit reinforcements 30, 50, and 70 by the pressure of the grout filler charged for each of the first and second compartments 30a, 30b ) (51) (71) through the first, second, third off-pit stiffeners 30, 50, 70 are provided to grout the grout filler to the outer region.

The tunnel excavation method using the pre-drilling reinforcement method before tunnel excavation according to the present invention comprises: a) forming a perforated hole at regular intervals on the upper part of the tunnel 10, and the first, second, and third reinforcement materials 30 )(50)(70) are installed, caulking between the hole inlet and the rear end of the first gangway reinforcement (30), and then the first, second, and third gangway reinforcements (30) (50) (70) inside and outside The step of grouting the ground outside the perforated hole by pressure grouting (S100), and b) curing the grout of the first, second, and third off-pit reinforcements 30, 50, 70, and installing the shaft door 200 ( S200) and, c) Excavating the tunnel to a certain distance (10) and repeating the installation of the support material 82 and the pouring of the shotcrete 83 (S300), and d) forming a hole from the inside of the tunnel 10 to the outside. And, the pit reinforcement 80 is installed inside the hole, and the pit stiffener 80 is installed so that the tail of the pit is located near the excavation surface of the tunnel 10, and a hole filling material ( 84) and then pressurizing grouting to the inside and outside of the pit reinforcement 80 and the ground around the perforated hole (S400), and e) when the stiffener 80 in the pit has fluidity or a chemical reaction is in progress. Including the step (S500) of excavating the tunnel 10 to a position where the rear end of the reinforcement material 80 in the pit is not exposed and pouring the support material 82 and the shotcrete 83 without waiting time for grout curing, the c) ~ e) Repeat the steps.

3 is a conceptual diagram of a method for reinforcing pre-drilling before tunnel excavation according to the present invention.

After cutting the original ground to a minimum, a large-sized external reinforcement as shown in Fig. 22 is installed on the surface stratum (soil layer), and a small external stiffener as shown in Fig. 21 is installed on the middle stratum (weathered rock), and the inner stratum (soft rock layer) In Fig. 22 provides a method for reinforcing drilling before tunnel excavation in which an external reinforcement of a size smaller than that of FIG. 22 is installed.

For example, 156m/m reinforcement is installed in the surface stratum (soil layer), 114m/m reinforcement is installed in the middle stratum (weathered rock), and 60.5m/m reinforcement is installed in the inner stratum (soft rock layer).

As described above, in installing the reinforcement outside the shaft by varying the perforation and reinforcing material specifications step by step, it is also possible to perform a straight drilling method of installing the reinforcement at the same time as the drilling step by step.

And in drilling the first hole 20, the second hole 40, and the third hole 60, a direct drilling method is used, and the first hole 20 or the second hole 40 ) In construction, it is advantageous to use a recovery bit. Material cost is reduced by repeatedly using bits.

In addition, the adjacent installation intervals of the outer stiffeners 30, 50, and 70 installed around the tunnel and the stiffeners 80 are wide at the front end and narrow at the sidewalls, or the installation interval is constant and the sidewall reinforcement is Install the auxiliary reinforcement 81 inside.

In addition, after installing the first, second, and third outboard reinforcements with the same standard, auxiliary reinforcements are additionally installed inside the outboard reinforcement for a certain section according to the ground characteristics, or an internal reinforcement is installed so as to overlap with the outboard reinforcement.

In addition, in the step-by-step installation of the out-of-pit reinforcement, the front and rear ends of the step-by-step out-of-pit reinforcement may be partially overlapped so that there is no shortage of shear force in any part.

In addition, after installing the off-pit reinforcement to a certain standard, auxiliary reinforcing materials may be additionally installed in the out-of-pit reinforcement in the part where reinforcement is required, so that the reinforcing force acts differently for each soil layer. In addition, if the tow on the shaft side is thin so that the earth pressure acts less and the earth pressure is larger inside, install an external reinforcement material with a certain size and then install an auxiliary stiffener in the inner section where the load is applied, or before the tunnel excavation inside the tunnel. In-pit reinforcement may be installed to overlap with the out-of-pit reinforcement. In this case, the size of the reinforcement material outside the shaft can be reduced.

In addition, auxiliary stiffeners in the stiffeners outside the pit and the stiffeners in the pit can be installed in the same section.

In addition, it is possible to install one more step above the shaft, and when installing one step further, the length of the installation may be shortened, and sufficient stability may be secured by installing in a certain standard while the reinforcing material standard is small.

In addition, even for a construction length of 40m or more, when drilling with different specifications by 15m each, it is the same as drilling once for 15m for each standard, so 15m drilling can be drilled with good directivity, so it is possible to drill in a straight line even over 40m. It is possible.

Figure 4 (a) shows an example of a method of installing an external reinforcement on the upper part of the tunnel before cutting the shaft in the original ground where the shaft portion is not cut.

Install the external reinforcement material in the designed position in the drilling hole so that the tail of the external reinforcement material comes to the end of the shaft, and install a quick-fixing material or a packer between the entrance of the drilling hole that will disappear when the shaft is cut off, and the tail of the external reinforcement material, and caulking is performed with the filling material in that part, and the shaft is cut off. It is removed upon removal or after grout. Any material or method of filling may be used to seal the gap between the rear end of the stiffener and the entrance of the hole.

In addition, according to the grout method, a tube-shaped guide pipe is connected to the rear end of the reinforcement material outside the mine and grouted in multiple stages while moving backwards from the inside of the reinforcement material outside the mine, or the simultaneous pressurization grouting method is used by installing one or more air jet hoses and grout hoses. May be.

In addition, when installing an extraneous reinforcement by adding one row, depending on the degree of reinforcement required, an additional extraneous reinforcement can be added only to the surface stratum (soil layer), or only the intermediate stratum (weathered rock) or the inner stratum (soft rock layer), and soil, weathered rock , It can be installed on both the inner stratum (soft rock layer), and can be installed without any difference in a certain standard.

4(b) shows an example of installation of an off-pit reinforcement with different specifications, and shows that the tip and the tail of a certain part are overlapped to effectively resist the upper load.

Figure 5 (a) is an example of adding an auxiliary stiffener inside the reinforcement outside the shaft of the present invention.

In the present invention in the section where reinforcement is further required as shown in the drawings, the standard of the off-pit reinforcement can be reduced by improving the shearing force by installing an auxiliary reinforcement inside the off-pit reinforcement.

Since auxiliary stiffeners are additionally installed inside the stiffeners outside the pit after the installation of the stiffeners outside the pit, the auxiliary stiffeners can be added at the required location without being restricted to the location or type, thus improving the stability very effectively.

By adding auxiliary reinforcing materials, the spacing can be widened, so it is economical.

As auxiliary reinforcing materials, any kind of reinforcing materials such as steel pipes, reinforcing bars, steel bars, square pipes, etc. can be exerted, and multiple uses are acceptable. It is also possible to install auxiliary stiffeners for each location as needed while making the standard of the stiffeners outside the mine.

FIG. 5 (b) shows a state in which a plurality of external reinforcements are connected in the same size and constructed, and shows several states in which a plurality of auxiliary reinforcements are installed. At this time, the auxiliary stiffener 81 installed on any one or more of the first, second, and third off-pit reinforcements 30, 50, and 70 is the first, second, and third off-pit reinforcement as shown in the enlarged view of FIG. 5 (b). 30) (50) (70) It is also possible to be selectively arranged to generate a large resistance force depending on the location of the inner center or edge.

It is a front view in which the external reinforcement material is installed in the tunnel direction of the present invention.

6 is an exemplary view showing a slip prevention system of the present invention.

Holes are formed below, above, left, and right of the tail of the external reinforcement material exposed to the shaft, and a fixing pin is installed between the through holes so that the caulking or filling material inside and outside the steel pipe is fixed and supported by the fixing pins This is to avoid being pushed out.

As a filling material in the reinforcement, it is not restricted by any material as long as it can fill the perforated holes such as pockets, cloths, and quick-setting materials.

In addition, it is possible to install a barrier film inside and outside the reinforcement material outside the pit, and install it as a filler from the barrier film to the entrance of the hole. The blocking film may be a pocket or a packer, or an inflatable material used in the present invention.

Figure 7 is an exemplary view of the installation of the reinforcement material outside the shaft and the reinforcement material in the shaft of the present invention.

This is a diagram illustrating a method for securing the stability of the tunnel before tunnel excavation by installing the internal reinforcement material before the tunnel excavation inside the tunnel during tunnel construction even though the external reinforcement material is installed.

After installing the external reinforcement, drilling the tunnel from the shaft, repeating the tunnel excavation, installation of support, and pouring the first and second shotcrete, and drilling upward at a designed angle from the excavation surface (membrane front) at a certain distance from the planned internal stiffener installation location. Do it.

The drilling position is the excavation surface and the film surface of the position to be removed during the next excavation and is located under the support material and shotcrete surface.

In this way, since the internal stiffener starts drilling at the excavation surface (film surface) below the support material and the shotcrete surface, it is possible to drill without interference between the support material and the shotcrete surface.

In addition, the perforation length must be longer than the inner stiffener, and the tail of the inner reinforcement must be installed so that it is near the upper excavation surface of the tunnel at the next excavation or the upper excavation surface of the tunnel at the next excavation, and is located between the support material and the support material that have not yet been installed. do.

In addition, it must be installed so as to pass the upper part of the support material that has not yet been installed, and it must be installed so that it goes further upwards past the location of the already installed external stiffener, and one or more of the internal stiffeners must overlap the external stiffener and a certain distance.

The support material and the support material are not specified at any position, and the first support material is the support material and the first support material is the rear (in the tunnel direction) than the place where the rear end of the internal stiffener is located (in the direction of the tunnel entrance). Jibojae is Jibojae.

The hole from the entrance of the hole formed on the excavation surface (the curtain surface) to the back of the internal reinforcement material located between the support material and the support material that has not yet been installed is a section that is removed during tunnel excavation, and a tube-shaped guide tube is drilled from the rear of the reinforcement material in this section. It connects to the outside or the inside of the hole, and after caulking the guide tube part, it can be pressurized to the internal reinforcement.

In another way, it is also possible to fill the hole from the entrance to the rear end of the inner stiffener with a filling material such as a quick-setting material, or install a packer and caulk, and then press grout the inner stiffener.

Since the internal stiffener is installed along the excavation surface of the tunnel, there are also sections that are installed almost horizontally in the direction of the tunnel progress. In this way, when the angle of the internal stiffener is small in the direction of the tunnel, the filler flows when filling the filler from the hole inlet to the tail of the stiffener. Blocking facilities can be installed so that the filling material does not flow into the rear part of the internal stiffener because it can go deep into the reinforcement.

In addition, after installing the internal reinforcement, when the hole is filled with a filling material between the rear end of the internal reinforcement and the entrance to the perforated hole, or when pressure grouting is performed on the internal reinforcement after caulking with a packer, the fluidity of the grout material is secured or a chemical reaction is in progress. Immediately after passing through the position of the unsupported support material (a) and the rear end of the internal reinforcing material not exposed, repeat the tunnel excavation, support material installation, and shotcrete placement more than once without waiting time for curing of the grout material.

In addition, before tunnel excavation, a certain part of the external reinforcement is overlapped with an internal reinforcement material, and when additional installation is required, the external reinforcement may be installed in a certain standard without any difference.

8 is an exemplary view showing the installation of a barrier film at the rear of the reinforcement material in the pit of the present invention and the installation of a filler material between the barrier film from the entrance of the perforated hole.

As a filling material, a packer, a pocket, a cloth, a quick payment material, etc. can be used.

Any method of filling the perforated hole is fine.

9 is another exemplary view of the present invention, which is a view that enables simultaneous compression grouting with an air jet hose and one grout hose.

When installing the air blowing hose and pressurized grouting hose outside the pit or inside the stiffener inside the pit, the tip and tail of the air blowing hose are penetrated, the tip is at the tip of the reinforcement material, and the tail is exposed outside the entrance of the hole.

The tip of the grout hose is in the position of the tip of the reinforcement material in a closed state, and the trailing end extends out of the opening of the perforation hole and is separated into two or more, and each separated part is connected to the grout pump. In addition, the grout hose inside the reinforcement forms through holes at regular intervals, and grout fluid is ejected through the through holes.

In this way, one grout hose and one air blowout hose are inserted into the reinforcement, so that when grouting, additional insertion of auxiliary reinforcing materials is very advantageous, and even pressure is transmitted to the entire perforated hole through the through holes formed at regular intervals. Since they are separated and connected to each pump, a large amount of grout can be grouted with great force, and other admixtures can be easily mixed and grouted.

It is also possible to add another grout hose.

In this case, the grout filler (grout liquid) and the admixture may be worked with different grout hoses.

10 (a) to (b) show exemplary diagrams for preventing rod sagging and preventing head sagging as a method for solving a problem in which the efficiency and straightness of the equipment is inferior due to the drilling equipment and tools during drilling.

The rod is a part of the drilling equipment and is made of a strong steel rod, and a certain width is drooped down by the weight of the steel rod. When drilling, the steel rod rotates while being hit, so it does not rotate at the same position, but draws a circle as much as the deflection. While rotating. In order to prevent such sagging of the rod, a method is shown as an example so that sagging does not occur by uniformly guiding the position of the rod in the perforated hole or steel pipe.

This is just an example and should not be limited to one way to ensure that the rod is well centered.

The rod deflection prevention system can be removed out of the perforated hole when removing the bit or before grouting. Alternatively, it can act as an internal stiffener and fix it with the grout.

FIG. 10(c) is also an exemplary view of several methods of improving the straightness without sagging the head by attaching a steel material to the tip of a reinforced steel pipe to reduce the sag of the head portion or straight movement due to faults.

It is to prevent sagging of the tip of the reinforcement by adding steel pipes, attaching a long piece of steel plate, or attaching reinforcement bars or steel bars to the outside of the reinforcement.

FIG. 11 shows a method of installing an expansion member, which is a blocking facility, inside or outside the steel pipe stiffener or in the section from the tail of the steel pipe stiffener to the entrance of the hole.

When the external pressure is removed, the expandable material acts as a partition to block the area where it swells up.After compressing the bulky expandable material in the shape of a tube, insert the expandable material guide device into the perforated hole, and then leave the expandable material at that location. By removing the expansion material guide device, the expansion material at that location swells up to form a barrier.

When the expandable material swells up to form a barrier layer, the expansion material is filled with a fluid admixture such as a quick-setting material, and then pressurized grouting is performed on the reinforcing material and the perforated hole.

The expansion material must be provided with a through hole so that the grout hose or air jet hose or auxiliary stiffener can penetrate, and must be fixed together.

Any material that swells up like a sponge when the compressed force is removed can be used for the expanding material.

In addition, the expansion material guiding device is not limited to the method as long as it is not only used in the form of a tube, but can be expanded inside the perforated hole.

12 (a) to (d) show that when there is a distance between the rear end of the steel pipe reinforcement and the entrance of the perforated hole, the material to be inserted into the invisible steel pipe reinforcement is easily inserted, and it is located between the rear end of the steel pipe reinforcement and the perforated hole to facilitate grout. It relates to an induction tube made of a tube shape for.

As an example of how to use the guide tube, connect the rear end of the reinforcing material and the guide tube after drilling, and make the rear end of the guide tube exposed outside the hole. The guide pipe extended from the rear of the reinforcement may be formed with a cutoff line or groove so that it can be easily removed.

The guide pipe is installed and removed according to the purpose of use, such as after grouting or after installing the insert inside the reinforcement or during tunnel excavation.

Figure 12 (a) is a reinforcing material is installed in the perforated hole and Figure 12 (b) is a guide tube is installed inside the reinforcing material. Figure 12 (c) is a grout hose installed in the guide tube and Figure 12 (d) shows a state in which the guide tube is removed.

The grout method using an induction tube can be used in both the simultaneous pressurization grout method and the multi-stage pressurization grout method.Also, you can install an inflated pocket inside or outside the induction tube, inflate it with air to caulk the perforated hole, and grout the inside and outside of the steel pipe reinforcement. There is also.

In addition, the tip of the guide tube can be bound to the aft of the steel pipe stiffener, and it can also be disassembled and used repeatedly.

In addition, when the inflating pocket installed outside the guide tube cannot be caulked due to expansion of only the pocket, a soft material is attached to the outside of the pocket to prevent the hole and gap.

13 to 17 show as an example a construction flow chart according to the method of reinforcing drilling before tunnel excavation of the present invention and a tunnel excavation method using the same.

13 shows a state in which a reinforcement is installed outside the pit after drilling with different specifications for each stratum, and pressurized and grouted together with a slip prevention system.

FIG. 14 is a view in which a shaft part structure is installed by connecting the rear end of an external reinforcement material after grouting is completed.

FIG. 15 is a diagram of excavating a tunnel up to a certain distance after completion of a shaft door, repeating installation of support materials and casting shotcrete, and excavating a tunnel.

Fig. 16 is a tunnel excavation to a certain length, installation of a support material and casting of shotcrete, and then drilling longer than the length of the stiffener in the pit at the excavation surface (membrane surface) at the bottom of the support material and shotcrete surface, and the tail of the stiffener in the pit is located below the planned excavation surface It is installed so that the rear part of the reinforcement material in the pit up to the entrance of the hole is filled with a quick-fixing material, and it is a diagram showing the state of pressure grouting inside and outside the stiffener in the pit and the ground around the hole.

FIG. 17 is a view showing a state in which the tunnel is excavated from the entrance of the drilled hole to the position where the rear end of the steel pipe reinforcement is not exposed and is out of the support material that has not yet been installed, and the state of installing the support material and casting shotcrete, and extending the excavation, and installing the internal reinforcement material. Depending on the ground conditions, the reinforcement in the mine can be repeatedly installed.

10: tunnel 20: first hole 22: filling material
24, 24': inner and outer caulking agent 30: first shaft outer reinforcement 32: extension
33: through hole 33a: fixing pin
34: expansion material 34a: through hole 40: second hole
50: second off-pit reinforcement 52: first overlapping portion 60: third perforated hole
70: third off-pit reinforcement 72: second overlapping portion 80: internal reinforcement
82: support material 84: hole filling material 83: shotcrete
90: bulkhead block 92: guide hole
A: Air blow hose G: Grout hose G1: Through hole
G2: Y-shaped tube G3: Injection tube G4: Guide tube
G5: telescopic member P: pump R: perforated rod

Claims (20)

Stratum scanning step (S10) of detecting the thickness of each stratum in the tunnel progress direction outside the tunnel excavation surface corresponding to the tunnel 10 shaft;
A plurality of first perforated holes 20 are formed at an angle of 6° or less based on the direction of tunnel progress outside the predetermined tunnel excavation surface at the entrance of the tunnel 10, and the first perforated hole 20 is expanded compared to the thickness of the surface layer. A first perforated hole forming step (S20) formed to a depth;
A first off-pit reinforcement construction step (S30) of reinforcing the surface stratum (1) by inserting the first off-pit reinforcement material 30 into the first perforated hole 20;
By inserting a perforated rod into the inner space of the first off-pit reinforcement 30 to form a second perforated hole 40 with a reduced diameter compared to the first perforated hole 20, the second perforated hole 40 is an intermediate layer ( 2) forming a second perforated hole perforated to an extended depth compared to the thickness (S40);
The second off-pit reinforcement 50 is inserted into the second perforated hole 40 through the inner space of the first off-pit reinforcement 30 to reinforce the intermediate stratum 2, and the second off-pit reinforcement 50 and the first A second off-pit reinforcement construction step (S50) of constructing such that the first overlapping portion 52 is formed in which the ends of the off-pit reinforcement 30 are engaged;
Inserting a perforated rod into the inner space of the first and second reinforcements 30 and 50 to form a third perforated hole 60 having a reduced diameter compared to the second perforated hole 40, and a third perforated hole 60 ) Is a third perforated hole forming step (S60) which is perforated to extend into the inner stratum 3; And
Reinforcing the inner stratum 3 by inserting a third extra-pit reinforcement material 70 into the third perforated hole 60 through the inner space of the first and second out-of-pit reinforcements 30 and 50, and the third out-of-pit reinforcement material ( A method for reinforcing pre-drilling before excavation of a tunnel comprising: 70) and a third out-of-pit reinforcement construction step (S70) of constructing a second overlapping portion 72 in which the ends of the second out-of-pit reinforcement 50 are engaged with each other. . delete The method of claim 1,
The first perforated hole 20 is inserted deeper than the first perforated hole 20, and the first perforated hole 20 is between the first perforated hole 20 and the first perforated reinforcing member 30 Filler 22 is poured in, and the filler 22 is provided to remove the shaft portion of the tunnel 10 during cut-out excavation. The method of claim 1,
An auxiliary reinforcement 81 is inserted into one or more of the first, second, and third off-pit reinforcements 30, 50, and 70, or an internal reinforcement 80 is installed from the inside of the excavation surface of the tunnel 10 to the outside. The first, second and third off-pit reinforcement materials 30, 50, 70 and the pre-drill reinforcement method before tunnel excavation, characterized in that provided so as to overlap with any one of the predetermined period. The method of claim 1,
After installing the first and second off-pit reinforcements 30 and 50 or the third off-pit reinforcement 70, partly excavate the entrance of the tunnel 10, and then the first and second reinforcements from the inside of the tunnel 10 excavation surface to the outside. , 3 The tunnel reinforcement 80 is installed at 8 ~ 25° to pass through the external reinforcement 30, 50, 70, and the rear end of the tunnel reinforcement 80 is a support material 82 to be installed near the planned tunnel excavation line. Pre-drilling reinforcement method before tunnel excavation, characterized in that the reinforcing material 80 is repeated at regular intervals while being positioned between the support material 82 and the neighboring support material 82. The method of claim 1,
When cutting and excavating the shaft of the tunnel 10, the rear end of the first off-pit reinforcement 30 is exposed to the outside of the first perforated hole 20 to form an extension 32, and a first off-pit reinforcement in the extension 32 (30) A plurality of through-holes 33 perpendicular to the longitudinal direction are formed, a fixing pin 33a is inserted into the through-hole 33, and a first hole corresponding to the inlet of the first hole 20 The inner and outer spaces at the ends of the stiffener 30 outside the shaft are closed by inner and outer caulking agents 24 and 24', and the inner and outer caulking agents 24 and 24' are outside by fixing pins 33a. Pre-drilling reinforcement method before tunnel excavation, characterized in that provided to prevent push in the direction. The method of claim 1,
A partition wall block 90 is provided which is inserted into at least one of the first and second off-pit reinforcements 30 and 50 so that the outer circumferential surface is in close contact with the inner circumferential surface of the off-pit reinforcement and a guide hole 92 is formed in the center, , The partition wall block 90 is a pre-drilling reinforcement method before tunnel excavation, characterized in that provided to rotatably support the perforated rod (R). The method of claim 1,
A plurality of grout holes 31, 51, 71 are formed on the outer circumferential surface of the first, second, and third off-pit reinforcements 30, 50 and 70, and the first, second, and third off-pit reinforcements 30) ( 50) (70) It is provided to simultaneously pressurize the inside and outside of the 1st, 2nd, 3rd pit reinforcement material 30, 50, 70 by injecting grout filler in the state in which the grout hose (G) is inserted. Pre-drilling reinforcement method before tunnel excavation, characterized in that. The method of claim 5,
Before tunnel excavation, characterized in that a hole fill material 84 is installed between the rear end of the pit reinforcement material 80 and the entrance of the hole where the pit reinforcement material 80 is installed, and the hole fill material 84 is provided to be removed during tunnel excavation Congenital hole reinforcement method. The method of claim 8,
Pressure grouting is performed by being inserted into the grout hose (G) and the air blowing hose (A) into the reinforcements 30, 50, and 70 outside the first, second, and third shafts, and the grout hose (G) is In this closed state, a plurality of through-holes (G1) are formed at regular intervals, a grouting filler injection pump (P) is connected to the rear part, and the air ejection hose (A) penetrates both sides, so that the tip is 3 It is disposed near the front end of the outboard reinforcement material 70, and the tail is exposed to the outside of the first out-of-pit reinforcement material 30, and is provided to discharge the air inside the first, second, and third off-pit reinforcements 30, 50 and 70. Pre-drilling reinforcement method before tunnel excavation, characterized in that. The method of claim 10,
The grout hose (G) has a trailing portion extending out of the first shaft reinforcement (30) to form two injection pipes (G3) by a Y-shaped pipe (G2), and connected to the pump (P) to each injection pipe. And, the pre-drilling reinforcement method before tunnel excavation, characterized in that provided so that the grouting filler is injected by each pump (P). The method of claim 10,
An expansion member 34 is installed between the rear end of the first external reinforcement material 30 and the entrance of the perforation hole, between the rear end of the internal reinforcement member 80 and the entrance of the hole, and a through hole 34a is formed in the expansion member 34 to form a grout hose. (G) and the air jet hose (A), characterized in that provided to be inserted through the pre-drilling reinforcement method before tunnel excavation. The method of claim 4,
An induction pipe (G4) is installed at the rear of the first external reinforcement member 30 or at the rear of the internal reinforcement member 80 to guide the entry of the grout hose (G), and the induction pipe (G4) is equipped with a grout hose (G). Pre-drilling reinforcement method before tunnel excavation, characterized in that provided to be removed after completion or when the tunnel (10) excavation. The method of claim 13,
The guide pipe (G4) is formed of the same material as the external reinforcement material and the internal reinforcement (80), or is formed of any one of a PVC pipe and a geosynthetic pipe, and the guide pipe (G4) is a first external reinforcement (30). ) And the reinforcing material 80 in the pit, which is integrally connected to the rear or installed detachably, and an elastic member (G5) is attached to the outside of the guide tube (G4) to caulk between the perforated holes. Pre-drilling reinforcement method. The method of claim 8,
The first plurality of first compartments (30a) are spaced apart from the inside of the first off-pit reinforcement (30) to form a plurality of first compartments (30a) inside the first off-pit reinforcement (30), and a first guide hole (94a) is formed in the center. A partition wall block 94 is provided, and is spaced apart from the inside of the second off-pit reinforcement 50 to form a plurality of second compartments 50a inside the second off-pit reinforcement 50, and a second guide hole ( A plurality of second partition wall blocks 96 in which 96a) are formed are provided, and a grout hose G is provided to be inserted through the first and second guide holes 94a and 96a, and the plurality of second partition wall blocks 96 The end of the second guide hole 96a of the second partition block 96 disposed in the front of the partition wall block 96 is formed with a locking protrusion 96b so that the end of the grout hose G is engaged and bound, and the first partition wall The block 94 and the second bulkhead block 96 are bound to each other by a traction rope 97, and a backslip prevention means 98 is installed on the outer circumferential surfaces of the first and second bulkhead blocks 94 and 96. The first and second reinforcements 30 and 50 are provided so that inward movement is allowed and outward movement is limited,
Before inserting the grout hose (G) into the first and second off-pit reinforcements (30) (50), the grout hose (G) is inserted into the grout hose (G) through the first and second guide holes (94a) (96a). When a plurality of first and second partition wall blocks 94 and 96 are inserted, and the grout hose G is inserted into the first and second off-pit reinforcement members 30 and 50, the end of the grout hose G Among the second bulkhead blocks 96, the second bulkhead blocks 96 that are disposed in front of the second bulkhead blocks 96 are hooked and bound to the first and second pit reinforcements 30 and 50 together with the grout hose G. As it moves, the adjacent first and second partition wall blocks 94 and 96 are inserted by the traction rope 97 while maintaining a predetermined distance, and when the grout hose G reaches a predetermined depth, the grout filler Is supplied and a grout filler is filled into the inside of the front second compartment 50a formed by the second bulkhead block 96 disposed in front of the plurality of second bulkhead blocks 96, and the internal pressure of the second compartment 50a When this rises, the second partition wall block 96 is prevented from being pushed by the backslip preventing means, and the grout filler is charged at high pressure, and then the grout hose G is placed at the distance between the second partition wall block 96 and the first partition wall block ( 94) is intermittently withdrawn as much as the distance between each of the first and second compartments (30a, 30b) is provided to fill the grout filler step by step, and the grout to be filled for each of the first and second compartments (30a) (30b) The first, second, and third off-pit reinforcement materials 30 through a plurality of grout holes 31, 51 and 71 formed on the outer circumferential surface of the first, second, and third off-pit reinforcement materials 30 by the filler pressure. ) (50) (70) Pre-drilling reinforcement method before tunnel excavation, characterized in that provided to grout the grout filler to the outer region. The method of claim 15,
The back-slip prevention means 98 has an inclined rail groove 98a extending to the rear end of the first out-of-pit reinforcement 30 on the outer circumferential surfaces of the first and second partition wall blocks 94, 96, and the inclined rail groove 98a Is formed at a downward inclination angle toward the center of the first and second bulkhead blocks 94 and 96 toward the rear end of the first off-pit reinforcement 30, and a stop ball 98b is inserted into the inclined rail groove 98a to cover 98c ) Is installed to be partially exposed to the outside, and when the first and second bulkhead blocks 94 and 96 move in the inward direction of the first and second off-pit reinforcements 30, 50, the stop ball 98b is inclined rail groove ( It moves to the deep end of 98a) to prevent friction with the first and second partition wall blocks 94 and 96, and the first and second partition wall blocks 94 and 96 are the first and second off-pit reinforcements 30 (50) When moving outward, the stop ball (98b) moves to the shallow end of the inclined rail groove (98a) and is pinched in a state of friction with the first and second partition wall blocks (94) (96), and the position is fixed,
The backslip prevention means 98 has one end connected to the outer circumferential surface of the first and second partition wall blocks 94, 96, and the other end at an outward inclination angle toward the outside of the first and second off-pit reinforcements 30, 50. It is formed of the formed stop piece (98d). Accordingly, when the first and second bulkhead blocks 94 and 96 move in the first and second pit reinforcements 30, 50, the first and second bulkhead blocks 94 and 96 are folded with the stop piece 98d folded. When the first and second bulkhead blocks 94 and 96 move outwardly, the first and second bulkhead blocks 94 and 96 are moved outwardly, and the first and second bulkhead blocks ( 94) Pre-drilling reinforcement method before tunnel excavation, characterized in that provided to be pinched in a state of friction with (96) and fixed in position. The method of claim 1,
In drilling the first perforated hole 20, the second perforated hole 40, and the third perforated hole 60, a direct perforation method is used, and the first perforated hole 20 or the second perforated hole 40 Pre-drilling reinforcement method before tunnel excavation, characterized in that a recovery bit is used during construction. The method of claim 4,
The adjacent installation intervals of the outer shaft stiffeners 30, 50, and 70 installed around the tunnel and the inner stiffener 80 are of a wide front end and a narrow sidewall, or the installation interval is constant and the sidewall side reinforcement is inside Pre-drilling reinforcement method before tunnel excavation, characterized in that the auxiliary stiffener 81 is installed on. The method of claim 1,
Tunnel excavation, characterized in that after installing the first, second, and third outboard reinforcements with reinforcements of the same standard, auxiliary reinforcements are additionally installed inside the outboard reinforcements for a certain section according to the ground characteristics, or an internal reinforcement is installed so as to overlap the reinforcements outside the tunnel. All congenital reinforcement method. Using the pre-drilling reinforcing method before the tunnel excavation of any one of claims 1, 4 to 6, 8 to 16, 18, 19,
a) Drilling holes are formed at regular intervals in the upper part of the tunnel (10), and reinforcements (30, 50, 70) are installed in the first, second, and third shafts in the hole, and the entrance of the hole and the outside of the first shaft. Caulking between the tails of the reinforcing material 30, and then grouting the inside and outside of the first, second, and third off-pit reinforcements 30, 50, and 70 to grout the ground outside the perforated hole (S100);
b) curing the grout of the first, second, and third off-pit reinforcements 30, 50, and 70 and installing the shaft door 200 (S200);
c) Excavating the tunnel 10 to a certain distance and repeating the installation of the support material 82 and the pouring of the shotcrete 83 (S300);
d) A perforated hole is formed from the inside of the tunnel 10 to the outside, and an intra-pit reinforcement 80 is installed inside the perforated hole, and the rear end of the inner reinforcement 80 is located near the excavation surface of the tunnel 10. After finishing the hole filling material 84 between the rear end of the reinforcing material 80 and the inlet of the perforated hole, pressure grouting to the inside, outside and the ground around the perforated hole in the reinforcing material 80 in the pit (S400); And
e) Excavating the tunnel 10 to a position where the rear end of the reinforcing material 80 is not exposed without waiting time for grout curing when the pressure grout filler has fluidity or chemical reaction is in progress. Including; the step of pouring shotcrete 83 (S500);
A tunnel excavation method using a pre-drilling reinforcement method before tunnel excavation, characterized in that repeating steps c) to e).

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