KR20130108218A - Method of reinforcement and construction of pillar of neighboring tunnel - Google Patents

Abstract

PURPOSE: A pre-reinforcement and excavation construction method for the pillar part of neighboring tunnels is provided to secure safety in an initial excavation work by excavating a tunnel with timbering effects. CONSTITUTION: A pre-reinforcement and excavation construction method for the pillar part of neighboring tunnels comprises the following steps: excavating the pre-excavation part of an existing tunnel (10) at a predetermined distance from a subsequent tunnel (11) in the longitudinal direction; boring the sidewall part of the existing tunnel with a pre-reinforcement material (20) exposed, inserting a plurality of pre-reinforcement materials, and grouting when the subsequent tunnel is excavated with a pillar part which passes through an unexcavated part (12) around the existing tunnel; placing the excavation surface reinforcement shocrete of a flat structure (40) on an exposed reinforcement material (20'), putting an anchor plate, and fastening a nut in the excavation of the subsequent tunnel; and excavating the unexcavated part to place the surface reinforcement shocrete on the exposed reinforcement material and fastening a nut with an anchor plate.

Description

Pillar part opening and digging construction method of adjacent parallel tunnel {METHOD OF REINFORCEMENT AND CONSTRUCTION OF PILLAR OF NEIGHBORING TUNNEL}

The present invention relates to a method and an excavation method for strengthening the pillar portion so that the ground between the tunnel and the tunnel can replace the pillar when constructing two or more tunnels in close proximity.

Among the terms used in the present invention, the preceding tunnel refers to a tunnel in which the tunnel excavation is completely or partially performed in the meaning corresponding to the trailing tunnel, and the trailing tunnel means securing a work space for reinforcing the pillar part before the trailing tunnel excavation in the preceding tunnel. In order to maintain a constant distance in the tunnel length direction for the tunnel to follow the neighboring tunnel adjacent to the preceding tunnel, the parallel tunnel means a tunnel in which the preceding tunnel and the trailing tunnel is installed adjacent to each other.

Recently, in the case of forming a tunnel with juxtaposition, it is designed to install at least 1.5 times the tunnel excavation width as a minimum interval for structurally ensuring safety.

However, obstacles at the entrance of the tunnel or excessive earthwork cutting can cause environmental problems, so it is sometimes necessary to narrow the tunnel separation distance to less than 1.5 times the tunnel digging width. In order to solve this problem, various methods of compressing restraint using tie rods or steel wires, which are reinforcing materials, have been proposed as reinforcing grounds between tunnels.

In the prior art, a technique for compressing between tunnels on both sides of pillar portions by using tie rods or steel wires has been proposed. Korean Patent No. 10-1096664 discloses inserting and grouting a conduit in a drilled hole, digging a trailing tunnel to a depth corresponding to the preceding tunnel, and inserting a tension member into each conduit connecting the preceding tunnel and the trailing tunnel. A technique of reinforcing the pillar part by pulling both ends of the tension member in the direction of compressing the pillar part using a binding member outside the pressure block installed outside the conduit and then grouting the inner part of the conduit into which the tension member is inserted is disclosed.

However, an unsolved problem in this prior art is that it is difficult to freely support the pillar sidewalls without compressive reinforcement since the pillar portion is left uncompressed until the trailing tunnel is excavated and put into the conduit immediately after the preceding tunnel excavation. It is not applicable to soft ground, and it is very difficult to install the precast faceplate to the conduit hole, and it is not possible to tightly attach the faceplate to the blasting or shotcrete surface so that it is directly placed on the drilling surface and completely attached. Occurs in a structure The bond shear strength is not developed, and the compressive force of the tension member is not applied to the ground to be reinforced with the structure in which the pre-conducted conduit supports the front plate so that only the restraining effect occurs after the relaxation deformation due to the initial excavation. In addition, the unconsolidated soil ground existing in the tunnel entrance and exit portion has a problem in that even if the ground itself restrains both sides of the pillar portion, the ground itself does not act as a pillar portion because it is a compressible material.

 Korean Patent No. 10-1028535, which is more prior art than the prior art, installs and restrains tie bolts in the pillar part from the preceding tunnel to the trailing tunnel side and injects the tie bolts into the micro cement milk when drilling is installed. And steel beams and reinforcing bars are formed by field assembly, which is merely a technique for giving sidewall restraint effect.

Another prior art, Republic of Korea Patent No. 10-0844104 is to support the compression on the frame on both sides by grouting the reinforcing bar into the pillar horizontally, only the restraint effect occurs on the original ground and the tension member is increased There is no effect of compressing the base by the elastic recovery force.

Initial displacement occurred during excavation Since the tension member inserted into the pillar part is passively acting like a nail with the entire drilling hole attached by grouting, the active structure in which the amount of deformation due to the prestress such as anchor is increased due to the amount of deformation of the axial force acting on the pillar part. More.

1 and 2 are a cross-sectional view and a plan view showing the structure of a proximity parallel tunnel according to the prior art. As shown in the figure, a hole is drilled in the pillar portion 2 located between the preceding tunnel 10 and the trailing tunnel 11, and a reinforcing material 20 is installed in the drilling hole, and the reinforcing material 20 is provided. Is drilled in the horizontal direction toward the trailing tunnel 11 while excavating the preceding tunnel 10 and inserted into the drilling hole and grouted to be fixed.

Referring to Fig. 2, there is shown a conventional method for excavating adjacent parallel tunnels, which is a plan view for drilling a tie rod by excavating to the side wall without leaving the pillar-side unexcavated portion of the preceding tunnel 10.

In this conventional method, first, reinforcement is performed after the pillar part is relaxed by the initial displacement occurring in the ground during tunnel excavation. Second, when pressure grouting is performed after inserting the reinforcement into the pillar part, the packer is attached to the wall of the pillar part. In the case of installation, if the ground is soft, the required depth 1.5 ~ 2.0m to withstand the restraint pressure is required to install the packer, and this part is not reinforced by grouting so that the pillar part, which is the purpose of the proximity tunnel, makes a thin tunnel. It is difficult, and thirdly, if the ground of the pillar part is difficult to stand on, such as a fault fracture zone, during the excavation, it is difficult to secure the independence time for reinforcement. Thus, the present prior art method has many problems.

To summarize the problems that are not solved in the prior art, it is important to compress both sides of the pillar portion with prestress immediately after the tunnel is excavated and before deformation occurs as quickly as possible, but the conventional technique is merely a constrained concept. It does not depart from the concept, it does not constrain the deformation of the pillars until the trailing tunnel is excavated and tensioned on both sides of the pillars, and the unconsolidated soils such as earth and sand, which are often present at the entrance of the shaft, are granular particles. There is a problem that the compressibility of the pillar portion is not improved and the rigidity is insufficient even when the pillar portion is restrained by the voids and water present therebetween. Therefore, there is a need for a technique for overcoming these problems.

In addition, when compressing both sides with grouting and prestress to reinforce the pillar part, the permeability of the ground itself decreases. Therefore, in the uncoated soil, when the upper part of the pillar part is saturated and the shear strength decreases due to the reduction of effective stress, the tunnel structure Since there is a decrease in safety, there is a problem in that a drainage passage through which the groundwater above the pillar portion can be drained smoothly is installed.

An object of the present invention was devised to solve the problems of the prior art, and additional stress and deformation occurs in the pillar portion due to the tunnel excavation, so that the deformation does not occur before reinforcing the pillar portion when excavating the preceding tunnel. The present invention provides a method of pre-drilling the remaining portion except for the relaxation area due to the excavation and perforating horizontally to penetrate the pillar portion to reinforce grouting by inserting a nail or an anchor in advance and further excavating the unexcavated portion.

 Another object of the present invention is to reinforce the pillar portion with a front attachment tie bolt such as a nail or an anchor capable of introducing prestress, and the plate structure 40 for reinforcing the pillar side wall is shotcrete or RSC (Rreinforce). Steel Cage) is installed on the side wall of pillar, and shotcrete is used to compress the side wall of pillar, and it shows the effect of supporting by exerting shear strength.

Another object of the present invention is that even in compressing the side wall of the pillar, the soft weathered rock or the soil ground contains air and water in the soil, so that the compressibility cannot be completely improved. It is to provide a method of design and construction so that the plate structure of the side wall of the pillar portion to act as a pillar as replaced by reinforced concrete.

Still another object of the present invention is to provide a method of excavating a tunnel after showing the pillar part on the out-of-cog ground surface when the soft ground and the toffee are shallow as described above.

In order to achieve the object of the present invention, the present invention, when excavating a close parallel tunnel, the pre-excavation except for the loosening region due to the line excavation, so that deformation does not occur in the pillar portion before reinforcing the pillar portion of the adjacent parallel tunnel In addition, it is achieved by drilling horizontally to penetrate the pillar portion including the relaxation region, inserting nails or anchors into the pillar portion in advance, reinforcing grouting and pre-strengthening, and additionally excavating the pillar portion side unexcavated portion, which is an unexcavated portion.

Trailing tunnel and in the direction of the tunnel First digging a pre-drilling portion of the preceding tunnel to maintain a constant distance;

Drilling and inserting a plurality of steel reinforcement reinforcement to the side wall of the preceding tunnel where the pillar portion is to be formed between the trailing tunnel and the preceding tunnel so as to be exposed when the pillar portion penetrates through the remaining pillar side unexcavated portion and excavates the trailing tunnel. Grouting;

Placing an excavation surface reinforcement shotcrete having a plate structure on the exposed reinforcement when excavating a trailing tunnel, and fastening a nut to a pressure plate;

Excavating the remaining pillar side of the preceding tunnel to excavate the reinforced surface shotcrete of the plate structure to the exposed reinforcement, and the pressure plate is characterized in that it consists of fastening the nut.

The reinforcing steel reinforcement is a form that can introduce prestress. Excavation of the remaining pillar part of the trailing tunnel and the preceding tunnel is excavated, and the exposed reinforcement is placed on the exposed reinforcement shotcrete reinforcement shotcrete, and the nut is pressed against the pressure plate after curing. It is characterized by applying a compressive force to the reinforcement in the pillar portion.

Excavation surface reinforcement shotcrete plate structure is characterized in that formed by installing a reinforce steel cage (RSC) on the excavation surface and pouring the shotcrete.

The grouting is characterized in that the pressure grouting.

Pillar reinforcement on the soft ground with shallow toffee is characterized in that before drilling the tunnel, the pillar is drilled vertically or inclined at a certain interval on the surface of the pillar to insert the micropile and pressurized grouting, and then the tunnel is excavated.

The drilling diameter of the drilling is characterized in that the pressure grouting by drilling to 76 to 150mm.

Perforated pipes are installed in the upper and sidewall portions of the pillar portion so that water does not pass through the shotcrete reinforced with the pillar portion so that drainage is induced so that the residual water pressure is not generated. It is characterized by not being caught.

The reinforcing steel reinforcement that can introduce tensile force is steel rod type, and the pipe-like fixture is fixed to both anchors fixed from the both ends by the rod margin, and both anchors are fixed to the steel rod by the stopper fixed to the steel rod on both sides. On the tip side, steel rod protective caps are fixed at both ends by screw joints to both anchorages, and the steel rods are PE coated and fixed with both fixtures and protective caps so that the steel rods are stretched by tension even when buried in grouting. It is coated with the exception of the protected nut ends and the PE sheath and the fixture are sheathed and joined by a shrink connection tube.

According to the present invention configured as described above, before the deformation occurs in the pillar in a state in which the pre-excavation part of the preceding tunnel is excavated and the unexcavated part is left on the pillar part side of the preceding tunnel, which is a relaxation region, the pillar part is penetrated through the unexcavated part of the preceding tunnel pillar part. As it reinforces and excavates, the deformation of the base can be reduced than the reinforcement after excavating the entire preceding tunnel, and the ground information such as jointing, elution water, and ductility of the base is checked in advance and the problem is corrected in the process of constructing the pre-excavation first. There is an effect that can afford to apply a variety of temporal margin and reinforcement method.

If the ground information obtained while digging the pre-excavation part is not secured by reinforcing the pillar part because the ground is soft, it acts like a pillar member replaced with the reinforced concrete column of the conventional Tachi tunnel by designing both side wall members of the pillar part thickly. In this case, the construction method has the effect of installing a strip-shaped RSC on the excavated side wall and hitting shotcrete while reinforcing the unexcavated portion at the pillar side by unit length.

RSC of the present invention is reinforced concrete and can be adapted to the effect of reinforcing the bond shear strength with the ground and can be adapted to the uneven surface of the excavation surface and reduce the amount of shotcrete rebound, using the construction joint reinforcement by freely designing the length and width of the RSC By connecting piece by piece is possible effect.

The tension member to reinforce the pillar part behaves like a nail by using anchors of both ends. The tension member can be easily tensioned by using a fixture like a shiatsu plate. The fixture resists friction and exhibits acupressure effect along with the plate structure. In this case, tension may be first introduced at one of both sides of the sidewall of the pillar part, and an extension amount of the tension member may be generated during tension, thereby allowing continuous prestress to be introduced by elastic recovery force.

In shallow and soft grounds, even though both sides of the pillars are constrained, the ground itself is compressible because the ground itself contains voids and water, so it is reinforcing method to drill the pillars vertically or inclined at regular intervals before tunnel excavation. After inserting and pressing grouting, the tunnel is excavated, and the pillar part is pulled from the surface to the micro pile, and the ground is pre-installed without stress deformation by tunnel excavation. Exercising has the effect of ensuring the safety at the time of initial drilling.

In addition, when reinforcing the both sides of the pillar part horizontally as a reinforcement material during the tunnel excavation, it is necessary to install and apply it at regular intervals so that the reinforcement material can be injected and reinforced horizontally into the pillar part so that the micro pile does not overlap. It can be effective.

1 is a view showing a method of restraining and reinforcing pillar portions of a proximity parallel tunnel according to the prior art in both tunnels.
2 is a plan view illustrating a method of excavating adjacent parallel tunnels according to the prior art.
Figure 3 is a cross-sectional view "AA" of Figure 6, excavating the preceding tunnel pre-excavation portion and drilled through the preceding tunnel pillar side unexcavated portion and pillar portion, and excavating the reinforcement material for the plate structure reinforcement It is inserted and installed in a length that exposes a certain length, and a packer is installed in the perforated hole formed in the left pillar side of the pillar part to press-inject cement milk to inject and reinforce the pillar part itself, and to integrate the reinforcement with the pillar part to behave together. It is a figure which shows that.
Figure 4 is a representative view of the present invention as a "BB" cross-sectional view of Figure 6, a plate structure reinforcement to the excavation surface in the following tunnel in the tunnel showing the state in which the nut is applied to the pressure plate to the exposed reinforcement.
FIG. 5 is a cross-sectional view of the section “CC” of FIG. 6, in which the leading tunnel and the trailing tunnel are excavated and the nut is fastened to the reinforcement on both sides.
6 is a plan view of FIGS. 3 to 5 in cross-sectional view.
FIG. 7 is a view illustrating a state in which a perforated drain pipe for draining groundwater that accumulates in the pillar part is installed upwardly inclined and horizontally.
8 is a cross-sectional view of reinforcing the pillar part by pre-installing the micro pile before tunnel excavation on the out-of-gang ground surface in the soft ground.
FIG. 9 illustrates the construction of the micro pile before the tunnel excavation on the out-of-the-ground surface in the soft ground, and the pillar portion penetrates between the micro piles pre-drilled by drilling the unexcavated portion of the preceding tunnel pillar portion, which is a relaxation region portion of the pillar side wall portion, in the preceding tunnel pre-excavation portion. This is a cross-sectional view of the composite reinforced by drilling, inserting and grouting as much as possible.
FIG. 10 is a cross-sectional view of the reinforcing material as shown in FIG. 9 and excavating a trailing tunnel to combine the reinforcing material into the tunnel plate structure and the pressure plate in the trailing tunnel.
FIG. 11 is a view illustrating a state in which the preceding tunnel and the trailing tunnel are completed in the pillar portion which is introduced into the micro pile.
12 is a view showing a modification to the ground joints are generated during the excavation of the tunnel in the presence of a four-way, not strong serves a view showing the weak form that is modified to a jointed direction generated in the pillar portion when tunneling.
Fig. 13 is a cross-sectional view of the RSC installed at the tip of the reinforcement 20 'exposed to the pillar excavation surface when the tunnel is excavated and cast shotcrete. The exposed reinforcement 20' is to cut the reinforcement margin. The length of the plate structure and the length as long as the nut tightening margin are added together. The reinforcement can use various kinds of steel bars, etc. If the steel bar is used as the reinforcing material, the steel bar margin becomes the reinforcement margin.
14 is a stereoscopic detail view of the RSC.
FIG. 15 is taken the line "YY" of FIG. It is a cross-sectional view and curves in the whole view as in the excavation line of the tunnel in partial view.
16 is a cross-sectional view taken along the line XX of FIG. 14.
FIG. 17 is a view showing a state in which a close parallel tunnel is used as a reinforcing material by using both anchor anchors.
FIG. 18 is a detailed cross-sectional view of a state in which prestress is introduced by installing a RSC shotcrete plate structure by installing a tensile force in a preceding tunnel and installing a pressure plate on the surface of the plate structure as a detailed view of FIG. 17.
Figure 19 is a detailed view of the protective cap mounted on both ends of the anchor anchor anchors.
20 is a detailed view of a tie bolt generally used in the prior art.
21 is a view reinforced with a rock bolt commonly used with a nail and a nail to strengthen the nail in the shaft in addition to the pillar reinforcement.

According to the present invention, when excavating a parallel tunnel, the distance between the tunnel and the tunnel is structurally without any problem, for example, when the distance between the tunnels is not greater than 1.5 times the tunnel excavation width. It receives a compressive force larger than that of a large one, and thus a structure receives a compressive force like a pillar. This part is called the pillar part 2, and is a technique regarding the method of reinforcing this pillar part 2. As shown in FIG.

When excavating the parallel tunnel, the earth pressure that the excavation surface was receiving becomes self-supporting as an arching force is formed around the tunnel. This arching force is overlapped in the base between the parallel tunnels, so that the compressive force is greater and the narrower the tunnel, the greater the stress. Therefore, the arching force must be reinforced to withstand the stress caused by the excavation.

The conventional method of reinforcing the pillar portion is reinforced by restraining the plate structure 40 using tie bolts as reinforcement on both sides of the parallel tunnel. In this case, the technical problem that cannot be solved is that the displacement occurring from the time of excavation to the installation of the tie bolt is not controlled. In other words, the time of excavation becomes an unsupported state. Since most of the deformation is completed, the soft ground collapses at this point.

The present invention With this in mind, when excavating the adjacent parallel tunnel, the parts except the loosening area due to the line excavation are pre-excavated so that deformation does not occur in the pillar before reinforcing the pillar of the adjacent parallel tunnel, Drilling horizontally to penetrate the pillar portion including the unexcavated portion 12 and inserting nails or anchors into the pillar portion in advance and reinforcing grouting to pre-reinforce and further excavating the pillar portion side unexcavated portion 12 which is an unexcavated portion. Applied to the pillar portion opening and digging construction method of the adjacent parallel tunnel characterized in that provided.

In this method, the pillar part is reinforced by drilling a drilled hole for opening the steel in the state of leaving the pillar part side unexcavated part 12 which is a relaxation area generated when the pre-excavation part 14 is excavated. (2) is to be supported while generating a stress in the reinforcing material from the moment of excavating the pillar-side unexcavated part 12 is reinforced and left with the reinforcing material 20 in an unrelaxed state.

When explaining the pillar-side unexcavated part 12 which is a relaxation area in detail, when a tunnel is excavated, an excavation surface will generate | occur | produce distortion in a perpendicular direction to an excavation surface, releasing the stress originally received in the ground by excavation. This deformation represents the maximum amount of deformation in the excavation surface and becomes smaller as it is deeper in the excavation surface, and varies depending on the type of soil, but at a depth of about 2m to 6m, the deformation amount becomes small. In the present invention, such a region is defined as a relaxation region, and the pillar portion side unexcavated portion 12, which is the toffee of the relaxation region on the pillar portion side, is secured so that the pillar portion portion to be reinforced is not relaxed, and the pillar portion at the outer excavation portion. (2) is drilled with a drill to penetrate, and the linear reinforcement is inserted into the pillar part and grouted.

In the process of constructing the pre-excavation part 14 first, the ground information such as jointing, elution water, and hardness of the ground can be checked in advance, and there is room for applying various time and reinforcement methods to compensate for the problem. will be.

The reinforcing steel reinforcement to reinforce the pillar is reinforced with a front attachment tie bolt such as a nail or an anchor capable of introducing prestress. After drilling and inserting the reinforcing material, grouting may reinforce the pillar base by pressing grouting according to conditions such as jointing, voids, etc. of the base.

It can be installed by changing the excavation order by applying various technical ideas of opening and drilling before leaving the pillar-side unexcavated part on the pillar-side tunnel base above to undergo stress deformation. After dividing the cross section up and down the excavation portion 12 and showing the pillar portion, it may be excavated.

FIG. 3 is a cross-sectional view taken along the line “A-A” of FIG. 6, and the line drilling portion 14 of the preceding tunnel 10 is first excavated. Then, the drilled hole is drilled horizontally from the pillar-side unexcavated portion 12 of the preceding tunnel toward the pillar-side predetermined excavation line of the trailing tunnel 11. The reinforcing material 20 is inserted into the drilling hole and grouted to be integrated with the ground of the pillar part.

FIG. 4 is a representative view of the present invention, which is a sectional view taken along the line "B-B" in FIG. 6, and the trailing tunnel 11 is excavated to the excavation scheduled line. When the excavation line is excavated to the predetermined excavation line, the reinforcing material 20 is exposed. At this time, after placing shotcrete to form the plate structure 40, the nut is fastened to the exposed reinforcing material 20 'by fastening a nut. In the state in which the nut is fastened to the exposed reinforcement 20 'by fixing or using the hydraulic jack, the exposed reinforcement 20' is tensioned with a hydraulic jack or the like, and then the nut is refastened as much as it is pulled to introduce a tensile force.

FIG. 5 is a cross-sectional view taken along the line “CC” of FIG. 6 and shows the preceding tunnel remaining in the preceding tunnel 10 after excavating the pre-excavation portion 14 and the trailing tunnel 11 of the preceding tunnel 10. Excavation of the pillar-side unexcavated portion 12 and excavation to the excavation scheduled line of the preceding tunnel 10 exposes the reinforcing material 20. At this time, after the shotcrete is formed to form the plate structure 40, the Anchor the pressure plate to the exposed reinforcement 20 'and simply tighten the nut, or tension the exposed reinforcement 20' while holding the nut to the exposed reinforcement 20 'using a hydraulic jack, and then hold it. Retighten the nut as much as you pull to introduce tension.

6 is a plan view of FIGS. 3 to 5 in the trailing tunnel 11 and the tunnel longitudinal direction; The pre-drilling portion 14 of the preceding tunnel 10 is first excavated to maintain a constant distance, and the preceding tunnel 10 in which the pillar part 2 is to be formed between the trailing tunnel 11 and the preceding tunnel 10. When the pillar portion 2 penetrates the multiple pillar steel reinforcement 20 through the remaining pillar portion side undrilled portion 12 to excavate the trailing tunnel 11, the drill hole is exposed from the drilling surface. And drilled by inserting the reinforcing material 20 into the drilling hole, and then exposing the reinforcing material exposed when the trailing tunnel 11 was excavated before the remaining pillar-side unexcavated part 12 of the preceding tunnel 10 was excavated. 20 '), excavated reinforcement shotcrete, which is a plate structure 40, is placed, and the nut is tightened with a pressure plate, and then the unreinforced portion 12 of the remaining pillar side of the preceding tunnel 10 is excavated and exposed. Construct the excavation surface reinforced shotcrete, which is the plate structure (40), on the 20 'and install the nut on the pressure plate. It is a figure which shows that it becomes.

When the hollow hole 13 formed in the remaining pillar-side unexcavated portion 12 is to excavate the remaining pillar-side unexcavated portion 12, the empty hole 13 is charged with the gunpowder to be used as a blasting hole. At this time, when the gun powder is charged, the stiffener 20 should be blasted so as not to damage by pre-inserting the cushioning material.

7 shows that the reinforcement of the pillar part 2 by grouting causes the water permeability coefficient of the base to be reduced to become an impermeable layer, so that the gore drain pipe 25 for draining the groundwater is inclined upwardly to remove residual water pressure. It is a figure which shows that it installed horizontally. The horizontal and inclined perforated drainage pipe 25 should be connected directly to the lower drainage of the tunnel with a hose so that it can be drained directly without passing through the shotcrete on the tunnel excavation surface.

In FIG. 3, the right preceding tunnel pre-excavation part 14 is pre-excavated and drilled through the unexcavated part 12 and the pillar part 2 in the preceding tunnel pillar part side, which is a loosening region, and the pillar part 2 both sides. When excavating the wall portion, the rod-shaped tension reinforcement 20 is inserted into a length that exposes a certain length for reinforcing the nut 68 and the plate structure 40, and the pillar-side unexcavated portion 12, which is the remaining excavation portion, is inserted. A packer is installed in an empty hole formed in the bottom to reinforce the pillar part 2 itself by injecting cement milk under pressure, and the reinforcing material 20 is integrated with the pillar part 2 to behave together. Then, when the reinforcing reinforcement 20 exposed by excavating the trailing excavation 11 is exposed, the plate structure 40 is installed on the excavation surface of the pillar part 2, and the nut is tightened by placing the pressure plate on the reinforcement 20. It can be crimped. When the trailing tunnel 11 is excavated, when the pillar part 2 and the preceding tunnel 10 pillar part side unexcavated part 12 remain unexcavated, the trailing tunnel is in a state where the center width of the parallel tunnel is thick. Excavation (11) and the plate structure 40 and the pressure plate to tighten the nut can be constructed in a more structurally safe state. Then, the excavation step is to excavate the preceding tunnel pillar-side unexcavated portion 12, install the plate structure 40 to the exposed reinforcement (20 '), and tighten the nut by pressing the pressure plate to press.

Referring to the first embodiment, the trailing tunnel 11 and the tunnel in the longitudinal direction The first excavation portion 14 of the preceding tunnel 10 is first drilled deeper to maintain a constant distance.

A plurality of stiffeners 20 are provided in the sidewall portion of the preceding tunnel 10 in which the pillar portion 2 is to be formed between the trailing tunnel 11 and the preceding tunnel 10. When the pillar part 2 passes through and excavates the trailing tunnel 11, the hole is drilled and inserted to grout so as to be exposed.

When excavating the trailing tunnel 11, the excavation surface reinforcement shotcrete, which is the plate structure 40, is poured on the exposed reinforcement 20 'and the nut is applied to the pressure plate.

The excavation surface-reinforced shotcrete, which is the plate structure 40, is placed on the exposed reinforcement 20 'by excavating the unexcavated portion 12 of the preceding tunnel pillar portion of the preceding tunnel 10, and the nut is pressed against the pressure plate. It is a method to introduce and excavate the pillar part of the adjacent parallel tunnel.

In addition, by attaching the pressure plate and the nut, the surface where the irregularities are formed can be additionally attached to the shotcrete for the waterproofing process.

Referring to the construction procedure of the first embodiment with reference to Figures 3 to 7, the pre-excavation portion 14 excavated reinforcing material 20 that can be tensioned using the space created by the excavation of the pillar portion unexcavated portion 12 ) And drills the drilled hole for the drilled steel to penetrate the pillar portion 2, and inserts only the required length so that the plate structure 40 can be installed on both sides of the pillared portion 2, and relaxes the drilled hole for the drilled steel. Pressurizing and grouting by installing a packer using the drilled hole of the pillar-side unexcavated portion 12 which is an area, and then, the plate structure 40 is exposed to the reinforcing material 20 'exposed by excavating the trailing tunnel 11. And pressing the pressure plate to tighten the nut, and the next step is to excavate the left pillar-side unexcavated part 12 and to fasten the nut against the plate structure 40 and the pressure plate.

The reinforcing steel reinforcement 20 is a plate structure 40 to the reinforcing material 20 'exposed by digging the unexcavated portion 12 of the preceding tunnel pillar portion of the preceding tunnel 10 as a form that can introduce a tensile force After casting and reinforcing the shotcrete reinforcement shotcrete, applying the tensile force to the reinforcing material 20 in the step of tightening the nut against the pressure plate to compress the pillar part 2 to apply the pillar part 2 of the adjacent parallel tunnel. Can showcase.

8 is a cross-sectional view of reinforcing the pillar part by pre-installing the micro pile 30 before the tunnel excavation in the out-of-the-glow ground surface in the case of soft ground such as soil which may be common at the entrance and exit of the tunnel.

9 to 11 show the micro pile 30 before the tunnel excavation in order to reinforce the pillar part 2 in the soft ground on the soft ground, and the preceding tunnel pre-excavation part 14 in the same manner as in FIGS. 3 to 5. Puncture the pre-tuned pillar portion side unexcavated portion 12, which is a part of the relaxed sidewall portion of the pillar portion, to perforate the pillar portion 2 between the pre-installed micro piles 30, and insert and reinforce the reinforcing material 20 to complex the composite. It is sectional drawing which shows the state reinforced by the.

FIG. 12 is a view showing a weak form in which a compression load acts on the pillars to cause slipping deformation in the jointing direction when the joint is present in the four directions 16 when the joint is present in the rock. It is a figure which shows the ground deformation which generate | occur | produces.

FIG. 13 is a cross-sectional view of the state where the RSC 41 is installed at the tip of the reinforcement exposed and exposed during the tunnel excavation and the shotcrete is poured.

FIG. 14 is a stereoscopic detail view of the RSC 41 of FIG. 13, and FIG. 15 is of FIG. FIG. 16 is a cross-sectional view taken along the line "YY", and FIG. 16 is taken along the line "XX" in FIG. Sectional view. In Fig. 15, 42 is a main reinforcing bar in the cross-sectional direction of the RSC 41, and 43 is a lower main reinforcing bar. 45 is a truss reinforcing bar connecting the main bars. In Figure 16, 44 is connected to the upper and lower rebar in the longitudinal direction by the truss reinforcement (45) to maintain the shape. 42 is a main bar and intersects at right angles with the longitudinal bar 44. 46 is a spacing stirrup.

FIG. 17 is a view showing a state in which a close parallel tunnel is introduced by using both anchoring anchors 60 as reinforcing materials.

18 is a detailed view of one end anchoring anchor 60, the reinforcing material of the present invention among the various types of reinforcing member as both ends anchoring anchor 60, the function, configuration, and construction method described in detail, the function is a tensile force It is possible to introduce from both ends of the anchor, and before the tension is introduced, the entire length is attached to the ground to be integrated with the ground by grouting in the drilling hole, so that when the ground is deformed, the ground is restrained.

The constitution is that both ends of the steel bar are threaded to fasten the nut, and the thickness of the plate structure 40 reinforcing the side wall of the pillar part 2 at both ends of the steel bar and the length for fastening the nut are called steel bar margins. Fixture stopper 71 is inserted into both sides of the steel bar and left by this length, and fixed with a stopper 71 fixed to the steel bar on both sides to tension the steel bar on one side, and the fixture stopper on the other side ( 71), the steel bar is fixed, and on the tension side, the tensile deformation caused by the tension is generated.

The tip anchorage is protected by a grout liquid by securing a steel rod clearance having a thread formed when grouting is carried out in a hole in which an anchor protection cap 66 whose end is blocked is screwed to both ends of the anchor. Both inner ends of both anchorages are fixedly coupled to a pipe-like fixture 63 having protrusions 64 formed on the outside thereof, and the fixing body and the steel bar are separated. When one of the steel rods is tensioned, the steel rods on the other side are fixed to the steel rods. The stopper 71 is fixed to the fixture coupled to the fixing unit 67, and the length of the fixture is determined by calculating the ground type and the tensile force.

Between the two fixing bodies 63, the steel bar is coated with PE, and the PE coating portion 62 and the fixing body are Coupled to a shrinkage connecting tube (69). Tension The coating with PE coating 62 and the fixing body is to free the deformation of the steel rod, which is a tensile material by the tensile force, in the grouted hole and to prevent permanent corrosion even if the cured grout is damaged such as cracks.

Sponge 70 wrapped on both sides of the anchor protection cap 66, when the excavation of the trailing tunnel 11 and the excavation of the pillar-side unexcavated portion 12, the protective cap 66 is damaged in the grouting If the protective cap (66) excavates the tunnel, and the damage is caused by the blasting, the sponge wraps the steel rod, which is a tension member, to protect the thread of the tension member from the shotcrete when the plate structure is shotcrete. Protect the sea stopper from deformation.

An advantage of both ends of the anchor anchor 60 is that the tension can be introduced by either of both sides of the tension can be introduced, and before introducing the tensile force can resist deformation of the base such as nail.

In order to reinforce the pillar, drilled through the pillar-side unexcavated portion 12 and the pillar portion 2 in the space of the preceding tunnel pre-drilling portion 14, and after grouting by installing a fixed anchor at both ends, When the anchor serves as a nail by the fixing bodies installed on both sides and excavates the trailing tunnel 11, after the plate structure is installed on the exposed anchor, the anchoring plate 60 is fixed to the anchoring plate when the anchor is fixed. It will act as an anchor.

When explaining the construction method, the plate which reinforces the pillar part side wall so that the pillar part 2 may penetrate through the pillar part 2 in the excavation surface of the pillar part side unexcavation part 12 in the space which excavated the pre-excavation part 14 of the preceding tunnel 10 is demonstrated. The thickness of the structure 40 and the length for fastening the nut are called steel bar margins. The length of the structure 40 is further drilled to allow the length of the length to be inserted into the anchor anchors and grouting, and then the trailing tunnel 11 is excavated to form a sponge. When the protective cap of the anchor protected by the exposed is exposed, install the plate structure to reinforce the tunnel excavation surface first, and after curing, remove the protective cap (66), install a pressure plate on the steel bar with exposed threads, and then combine the nut, hydraulic jack Introduce the required tension force and tighten the nut further when the increase occurs.

Then, the tensile force is introduced into the pillar portion 2 to form a prestress.

Next, when the anchor side is exposed by digging the pillar portion side unexcavated portion 12 of the preceding tunnel 10, the plate structure 40 is installed, and then the protective cap 66 is removed to the pressure plate 65 and the nut 68. Tightening is possible, and an additional hydraulic jack can be used to introduce additional tension.

The introduction method of the tension force is connected by a steel rod connected to the hydraulic piston and a screw-shaped coupling hole, the reaction force connected to the cylinder portion is supported by the plate structure 40 reinforcing the side wall of the pillar portion 2 is tensioned.

Both types of anchoring anchors (60) as a type of steel reinforcement (20) having a function of introducing a tensile force is fixed to both anchorages (67) are fixed to the rod is inserted into the outside of the rod-shaped both sides spaced apart from both ends by the steel rod margin. Both anchors are fixed to the tensile force of the steel rod by a stopper fixed to the steel rod on both sides.

On the front end side, the steel bar protective cap 66 is fixed to both fixing holes 67 by screwing. Even if it is buried in grouting, the steel bar is covered with PE cover 62, except for the fixing unit coupled to both anchors and both ends of the nut protected by the protective cap 66. The abdomen and the fixture are sheathed with a shrink connection tube 69.

When excavating the trailing tunnel 11 or the pillar-side unexcavated portion 12, the tip of the pre-reinforced reinforcement is protected with a protective cap 66 and a sponge so as to be easily exposed without damage, and after reinforcing plate structures such as excavation and shotcrete, Remove the protective cap 66 and the sponge.

Excavation surface reinforcement shotcrete, which is a plate structure 40 for reinforcing the side wall of the pillar part 2 with bearing pressure and bond shear strength, uses a general shotcrete as the plate structure 40 or RSC 41 is installed on the excavation surface. The RSC 41 is manufactured by welding the reinforcing bar in the direction of the tunnel section in the form of truss, as shown in FIG. If it is short within the truss reinforcement (45) without reinforcement to the stirrup reinforcement (45) is attached to the reinforcement reinforcement (20) to be released to combine with a pressure plate to form the shotcrete by curing.

In addition to the various plate structure 40 can be devised and applied.

If the ground is soft and the pillar structure (2) side plate plate (40) only needs to be a pillar in addition to the function of compressing only the pillar structure (2) both side wall plate structure (40) to the pillar part (2) It can be used as a wall structure that acts as a column by designing a thickness so that it can receive a working load.

In this case, the base portion of the side wall is a base structure that can increase the bearing capacity by installing a bottom plate in the lower portion of the plate structure 40 to withstand the bearing force, or to further reinforce the foundation by constructing a micropile in the bottom plate. The upper part of the side wall should be designed and connected to the plate structure 40 supporting the tunnel excavation surface. In this case, the width of the pillar portion 40 can be reduced thinner. The method of estimating the load is assumed to be one minimum large cross-section tunnel including the leading tunnel 10 and the trailing tunnel 11, and the ground load between the inner cross section of the large cross section tunnel and the inner cross section of the adjacent parallel tunnel is applied. In the case of low toffee, which is assumed to act as a function or does not form arching, the self-weight of the ground can be calculated as the load to the surface between the centerlines of two parallel tunnels.

In addition, even if the toffee is shallow and soft, both sides of the pillar part 2 are constrained, and the ground itself is compressible because it contains pores and water in the soil. Thus, the pillar part 2 before the tunnel is excavated as shown in FIG. 8. ) Is drilled vertically or inclined at regular intervals to insert the micro pile and pressurized grouting, and then the tunnel is excavated.

In addition, as shown in the construction sequence of FIGS. 9, 10, and 11, when the tunnel side is to further reinforce both sides of the pillar part 2 horizontally with the reinforcing material 20, the pillar part 2 so that the micro pile does not overlap. The reinforcing material 20 is inserted into the perforation horizontally, and the reinforcement injection material may be injected at regular intervals so as to be reinforced by injecting. The reinforcement injection material may be used by mixing various injection materials such as cement and micro cement with water.

In this case, the drilling diameter for inserting the micro pile is 76 ~ 150mm, and the grouting is good in construction. The softer the ground, the more structurally advantageous the larger the diameter is in order to increase the grout bulb and friction area.

In addition, when compressing both sides with grouting and prestress to reinforce the pillar part 2, the permeability of the ground itself decreases, so that the upper part of the pillar part 2 is saturated with the groundwater and thus effective stress. When the shear strength decreases due to the decrease, structural safety of the tunnel decreases. Therefore, when designing a drainage tunnel, a drainage path for smoothly draining the groundwater above the pillar part 2 should be installed. At this time, the drained water should not pass through the shotcrete because chemicals in the tunnel shotcrete are dissolved in the water and react with the carbon dioxide in the air to produce white matter.

Therefore, after reinforcing the pillar portion 2, a hole drain pipe 25 should be installed in the upper portion and the side wall portion of the pillar portion 2 so that water does not pass through the shotcrete so that drainage is induced and the residual hydraulic pressure is not applied.

FIG. 18 is a detailed view of FIG. 17, in which a tensile force is introduced in the preceding tunnel 10 to install the RSC 41 shotcrete plate structure 40, and a pressure plate 65 is installed on the surface of the plate structure 40 to introduce prestress. It is sectional drawing of the both ends fixation anchor 60 which can be made.

19 is a detailed view of a state in which the protective cap 66 is fixed to both ends of the fixing anchor 60 at both ends. The sponge 70 may be attached so that the protective cap 66 is easily exposed during the excavation.

20 is a detailed view of a tie bolt commonly used in the prior art.

FIG. 21 is a view of reinforcing nail nails 80 used to show nails in the gang in addition to pillar reinforcement, and rock bolts 81 generally used.

When reinforcing pillars, the spacing and quantity of stiffeners are determined by the designer's judgment and structural calculation depending on the tunnel size, ground condition and pillar thickness.

2: pillar 10: leading tunnel
11: trailing tunnel 12: pillar portion unexcavated portion
13: empty space 14: leading tunnel pre-excavation
20: reinforcement 20 ': exposed reinforcement (reinforcement margin)
21: tie bolt 25: hole drain pipe
30: micro pile 40: plate structure
41: RSC (Reinforce Steel Cage) 60: Both Ends Fixed Anchor
61: steel rod 62: PE tube
63: fixture 64: fixture protrusion
65: pressure plate 66: protective cap
67: anchorage 68: nut
69: connection shrink tube 70: sponge
71: stopper 80: nail polish
81: rock bolt

Claims (10)

When excavating the adjacent parallel tunnel, the excavation of the pillar portion 2 of the adjacent parallel tunnel is pre-excavated except for the relaxation region due to the line excavation, so as not to deform the pillar portion 2 before the reinforcement. Perforated to penetrate the pillar portion including the non-side portion 12, the nail or anchor is inserted into the pillar portion 2 in advance, reinforcement grouting to reinforce the line, and further excavation of the pillar portion side unexcavated portion 12 which is an unexcavated portion Pillar portion opening and digging construction method of the adjacent parallel tunnel characterized in that it comprises a step.
First digging deeper into the predrilling portion 14 of the preceding tunnel 10 so that a constant distance in the longitudinal direction of the trailing tunnel 11 is maintained;
A plurality of stiffeners 20 are provided in the sidewall portion of the preceding tunnel 10 in which the pillar portion 2 is to be formed between the trailing tunnel 11 and the preceding tunnel 10. When the pillar portion 2 penetrates through and excavates the trailing tunnel 11, drilling and inserting and grouting the exposed steel reinforcement 20 so as to be exposed;
Placing an excavation surface reinforcement shotcrete, which is a plate structure 40, on the exposed reinforcement 20 ′ when excavating the trailing tunnel 11, and fastening a nut to the acupressure plate;
Excavation of the remaining pillar portion unexcavated portion 12 of the preceding tunnel 10, and the excavation surface reinforcement shotcrete, which is the plate structure 40, is placed on the exposed reinforcement 20 'and the nut is pressed against the pressure plate. Pillar buoyancy and excavation construction method of the adjacent parallel tunnel characterized by.
The method according to claim 2,
The reinforcing steel reinforcing material 20 is a form that can introduce the prestressed excavation surface of the plate structure 40 to the exposed reinforcement 20 'by excavating the remaining pillar-side unexcavated portion 12 of the preceding tunnel 10 Method of pouring and excavating the pillar part of the adjacent parallel tunnel, applying compression to the pillar part 2 by placing a reinforcing shotcrete and applying a tensile force to the reinforcing material 20 in the step of fastening the nut to the acupressure plate after curing.
The method according to claim 2,
Excavation surface reinforcement shotcrete that is the plate structure 40 is installed on the excavation surface RSC (41) (Reinforce Steel Cage) to install the shotcrete pillar pillar opening and drilling method of the adjacent parallel tunnel, characterized in that formed.
The method according to claim 2,
Wherein the grouting is a pressure grouting pillar portion of the adjacent tunnel, the pillar portion opening and drilling method of the adjacent parallel tunnel.
The method according to claim 2,
The reinforcement of the pillar part 2 consisting of soil sand in the soft ground with shallow toffee is required to drill a drill hole vertically or inclined at a certain interval from the ground surface to the pillar part 2 before inserting the tunnel and inserting the micro pile and pressing grouting. Pillar part introduction and excavation construction method of the adjacent parallel tunnel, excavating the tunnel.
The method of claim 6,
The drilling diameter of the drilling hole is 76 to 150mm perforations, pillar portion opening and digging construction method of the adjacent parallel tunnel, characterized in that the pressure grouting after drilling.
The method according to claim 2,
To prevent water from passing through the shotcrete reinforcing the pillar portion 2, an inclined or horizontal hollow hole drain pipe 25 is upwardly installed in the upper portion and the side wall portion of the pillar portion 2 so that the residual water pressure is not applied. Pillar buoyancy and excavation construction method of the adjacent parallel tunnel characterized in that.
The method according to claim 2,
The side wall portion of the pillar portion 2 capable of withstanding the load acting on the pillar portion 2 so that the plate structure 40 simultaneously compresses the pillar portion 2 side and functions to serve as a pillar. The plate structure 40 is calculated by designing the thickness, and the part connected to the tunnel bottom of the plate structure 40, the pillar portion opening and digging construction method of the adjacent parallel tunnel, characterized in that the design as a basic structure.
     As a steel bar reinforcement (20) capable of introducing a tensile force, the pipe-like fixture in the form of a steel rod is fixed to both anchorages 67 fixed apart from both ends by a steel rod margin, and both anchorages 67 on both outer sides. The tensile force of the steel rod is fixed by the stopper 71 fixedly coupled to the steel rod, and the steel rod protective cap 66 is fixed at both ends by screw joints at both ends, and the steel rod is tensioned even when it is buried in grouting. The steel bar is coated with PE covering 62 except for both the fixing body 63 coupled to both anchors and the nut fixing portions protected by the protective cap 66, and the PE coating 62 so as to extend by the PE coating 62. A pillar part expansion steel anchor of a close parallel tunnel, characterized in that the fixture (63) is sheathed with a shrinkage connecting tube (69).

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