JPH07217364A - Forming method of groove-shaped continuous pit - Google Patents

Abstract

PURPOSE:To form a groove-shaped continuous pit capable of forming a free surface having high accuracy to a bedrock. CONSTITUTION:Annular pits are shaped in a bedrock surface 1 by operating annular boring drills 13 loaded on a drill 10 while the directions of the drilling of the boring drills 13 are controlled as using core sections 1A being formed in a cantilever cylindrical shape and left and formed in a bedrock as guide cores. Boring drills 14 means are moved so as to shape specified superposing sections to annular pits 3 at places adjacent to the core sections 1A, and annular pits 4, are formed successively while leaving and forming the core sections 1A in the bedrock, thus forming a continuous groove-shaped section.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a grooved continuous hole, and more particularly to a method for forming a grooved continuous hole suitable for forming a free surface on an excavated surface in rock excavation such as a medium-hard rock tunnel. Regarding

[0002]

2. Description of the Related Art Conventionally, a blasting method has been adopted for excavation of medium-hard rock mountain tunnels and excavation of rock for light construction.
Although this blasting method is economically and constructionally excellent, it has problems in that the vibration generated by blasting affects existing structures and noise. Therefore, recently, a controlled blasting method or a split rock method without blasting has been adopted in a tunnel close to a residential area or an existing structure. Among them, in order to increase the efficiency and accuracy of controlled blasting and to perform efficient block breaking by the split rock method, a method of forming a free surface composed of grooved continuous holes in a tunnel face is adopted. An example of the free surface formed on this tunnel face is shown in FIG. For example, there is an excavation method in which free surfaces 51 and 52 formed of groove-shaped continuous holes are formed on the entire surface of the tunnel face 50, and each independent rock block 53 is cantilevered and removed by a breaker or the like. In addition, a substantially arc-shaped free surface 54 consisting of a groove-shaped continuous hole is formed along the contour of the upper half of the tunnel, and the rock 55 around the tunnel and the face face 50 of the tunnel are cut off so as not to damage the surrounding rock. In many cases, high precision drilling is performed.

Various excavators as shown in FIG. 6 have been developed as a boring device for forming such grooved continuous holes. FIG. 1A shows an example of an excavator equipped with multiple rods capable of forming grooved continuous holes at one time. In the excavator 60 shown in the figure, five rods 62 are operated by the operation of a gear box 61 that transmits a driving force of a drill (not shown).
, 63 ... can be simultaneously rotated, hit, and fed. A bit 64 is attached to the tip of each rod 62, 63.
The 65 are mounted so as to form two rows in front of and behind the tunnel face. By arranging the bits 64 and 65 in this way, it is possible to form the groove-shaped continuous hole in the range shown by the broken line only by feeding the excavator 60 toward the face of the face.

FIG. 6B shows a plate shape having two guide hole drilling rods 66 for forming circular guide holes and a line bit 68 for excavating a linear groove shape between the two guide holes. A rocking drill type excavator 70 having a rocking portion (swing plate) 69 is shown.

[0005]

By the way, the excavator as described above is of a type in which a continuous solid hole is formed in the rock mass at the tip of the bit by impact, rotation, etc. transmitted from the rod, Since the hole drilling direction is defined by using the surrounding rock mass where the solid hole is drilled as a guide, hole bending may occur depending on the surrounding rock mass condition. For this reason, an excavator in which a rod guide is provided on the excavator side has been proposed, but when the rod begins to bend in the bedrock, this rod guide may not be able to sufficiently regulate the drilling direction of the bit at the tip.

Therefore, the object of the present invention is to solve the above-mentioned problems of the prior art, and in the state where the drilling is in progress, the drilling is performed by the guide portion formed of the core portion remaining formed in the rock mass itself. Based on a new idea of guiding a bit, it is to provide a method for forming a groove-like continuous hole capable of forming a highly accurate free surface on a tunnel facet or the like.

[0007]

In order to achieve the above object, the present invention provides that an annular hole is formed on a rock surface by the operation of an annular drilling means mounted on an excavator.
While controlling the drilling direction of the drilling means using the core portion which is cantilevered and remains in the bedrock as a guide core, a predetermined overlapping portion with the annular hole is provided at a position adjacent to the guide core. The hole forming means is moved so as to have the guide core, and the annular core is sequentially formed while the guide core remains formed in the rock to form a continuous groove portion.

In this case, the drilling means are arranged so as to be in parallel with each other at a predetermined interval so as to face the face of the face, simultaneously form a plurality of annular holes, and the annular holes are made continuous to form a groove. It is preferable to form a groove.

[0009]

According to the present invention, the annular hole is formed on the rock surface by the operation of the annular drilling means mounted on the excavator, and at the same time, the annular hole is formed in the cantilever shape and remains in the rock. The core portion is used as a guide core to regulate the drilling direction of the drilling means, and the drilling means is moved so as to have a predetermined overlapping portion with the annular hole at a position adjacent to the guide core. Since the annular hole is sequentially formed while the guide core remains formed in the inside, and the groove portion is formed by connecting the annular holes continuously, the circular hole used for the conventional drilling of the circular hole. Since the annular hole having a hole area substantially equal to the hole cross section of the bit is formed, the hole energy introduced into the bit can be drilled with the same hole energy as that in the conventional case. At this time, the hole is formed in the hole forming means. As a guide core for drilling the core Highly progressive drilling can be performed, and drilling can be performed accurately also in the part adjacent to the existing hole where the free surface has already been formed, and a series of continuous drilling can be performed to accurately place the groove-like continuous hole at a predetermined position. Can be formed.

In this case, the drilling means are arranged such that a plurality of them are arranged in parallel at a predetermined interval so as to face the face of the face, and at the same time, a plurality of annular holes are formed and the annular holes are made continuous to form a groove. It is possible to quickly form the continuous holes that form the ridges.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the method for forming grooved continuous holes according to the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a construction sequence diagram showing a construction state in a step of forming a groove-shaped continuous hole according to the present invention. In the present embodiment, a tire traveling excavator in which an annular shank as an annular drilling means shown in FIG. 4 is mounted in a drilling drive unit is shown as an excavator (only the front part is shown in the same figure). Has been). The tire traveling type excavator 10 (hereinafter referred to as an excavator 10) has a swing base 11 mounted on a bogie 17 capable of self-propelled by a tire traveling in a tunnel, and a work arm supported by the swing base 11. 12, lateral movement means 14 capable of moving the drill 13 to a predetermined position by the working arm 12, and the lateral movement means 14
With a vibration rotary motor 15 mounted so as to be slidable laterally at each drilling pitch, and a drill 13 to which a rock drill 15 represented by this vibration rotary motor is given a driving force consisting of rotation and impact. It is configured. The tip portion of the drill 13 surely applies the driving force to the drill tip 13a.
And a ring bit 20 connected to the casing rod 16 (hereinafter, when the rock drilling portion is generically described, the drill 1 is used).
Write 3. ).

As shown in FIG. 4, the annular bit 20 has an outer diameter of 200 mm and an inner diameter of 180 mm in this embodiment.
Is a hollow tube made of a hard alloy having an annular shape. The hole cross-sectional area is slightly larger than that of the conventional circular bit (φ50 to 60 mm) as shown in FIG. 5, but the outer diameter can be set large because it is hollow. Further, a metal chip 22 having a predetermined shape is partially fixed and fixed to the tip end surface 21 of the annular bit 20. The metal tip 22 has a diameter of 3-4 than the inner / outer diameter of the annular bit 20.
It is formed so as to project by about mm, and when the rock is crushed, an inner and outer annular clearance having a predetermined thickness is formed between the inner and outer surfaces of the annular bit 20 and the rock surface. Flushing water containing fine crushed fragments flows out from the face side to the rear through this annular clearance part,
The crushed pieces (sludge) generated at the tip of the hole are discharged to the outside of the hole. At this time, the flushing water is supplied from the rear to the cutting face position along the pores formed in the thick portion of the annular bit 20 in the longitudinal direction of the pipe.
A casing rod 16 that transmits the driving force from the rock drill 15 is connected to the annular bit 20. The casing rod 16 is also a hollow tube having an inner diameter substantially equal to that of the annular bit 20, and has extremely high torsional rigidity so that a strong transmission rotational force can be transmitted to the annular bit 20 without loss. Further, a core shooter 26 for discharging a cylindrical guide core (described later) crushed to a predetermined length to the outside of the rod is formed at a rear position. The applicant has already jointly proposed an invention relating to this type of tunnel excavator (Japanese Patent Application No. 5-19336).
(See No. 7).

FIG. 1 (a) shows a state in which the excavator 10 described above is made to face the tunnel tip face 1 with the drill tip 13a of the excavator 10. In the excavator 10, the working arm 12 is moved to a position where the drill tip 13a comes to the end 2 of the continuous hole drilling position, and the rock surface is supported by the outrigger (not shown). It can support the reaction force.

Further, in this embodiment, the horizontal intervals of the drills 13 arranged in parallel in the horizontal direction are set to four times (4D) the drilling pitch. Further, the drill 13 can be slid laterally on the traverse means at every hole pitch (D). From this state, as shown in FIG. 2B, the entire drill 13 is fed toward the face of the cutting face while rotating and striking the two drills 13, and the first hole 3 of the face 1 is drilled. To start. At this time, as shown in FIGS. 3 (a) and 3 (b), the annular bit 20 portion of the drill tip 13a drills the rock mass in an annular shape with the core 1A left inside. Since the core portion 1A is located as a guide core in a hollow portion within a range extending to the annular bit 20 or the casing rod 16 during excavation, straightness at the time of feeding is maintained even if the entire drill 13 is shaken by vibration at the time of drilling, It is possible to prevent bending of holes.

In FIG. 1 (c), when the boring of the first hole 3 is completed, the position of the carriage 17 of the excavator 10 remains unchanged,
The rock drill 15 on the traverse means 14 is moved laterally by the drilling pitch to drill the second hole 4. At this time, since the second hole 4 is positioned so as to overlap a part of the already drilled first hole 3, the second hole 4 is drilled with a free surface formed by the first hole 3 on one side. For this reason, normally, the drill tip 13a flows to the free surface side to cause hole bending. However, in the present application, as described above, the remaining core portion 1A in the annular bit 20 functions as a guide core, the straightness of the drill is maintained, and a new hole adjacent to the free surface (existing hole) can be accurately formed. it can. By repeating the above-described hole making step, the groove-shaped continuous hole 5 as shown in FIG. 7D can be formed.

FIG. 2 is a schematic front view and a sectional view showing an enlarged view of the formed groove-shaped continuous hole 5. The same figure (b)
After the groove-shaped continuous hole 5 is formed as shown in FIG. 5, a part of the core portion 1A that has been broken and discharged remains. This core 1
As described above, A is formed as a cantilevered cylindrical block over the inside of the annular bit 20 or the casing rod 16 as the drilling progresses. Normally, vibration transmitted through the rock mass during drilling, the annular bit 20 and the casing rod 16 are formed. Since it breaks in the middle due to the vibration of 16, the root portion remains on the face face after drilling. At this time, a wedge-shaped crushing tool (not shown) is provided between the cores 1A remaining on the facet.
By inserting and pressing the tip of the core 1A from the side as shown by the arrow, a crack 7 can be generated from the root portion of the cantilever and the remaining portion can be removed.

In addition, when there are many cracks due to the fact that joints 8 are developed in the rock excavating the tunnel, as shown in FIG.
Immediately after the core portion 1A is formed as shown in (c), the core portion may be broken at a slight position from the root portion. However, even in such a case, since the drill tip 13a slightly acts as a guide core, no hole bending occurs. In addition, when the core is broken in the annular bit 20 as described above, the broken portion is sent inside the casing rod 16,
It can be discharged from the core shooter 26 shown in FIG.

The excavator 10 used to form the groove-like continuous holes described above is not limited to the type in which the double drills 13 shown in FIG. 5
It is also possible to use two or more multi-drills similar to the excavator 60 shown in FIG. 1 or to use a drilling machine equipped with only one drill in case of a small-scale cross section. Further, it goes without saying that the outer diameter and the wall thickness of the annular bit 20 described above can be appropriately set according to the capability of the mounting hole drilling motor. Further, although the present embodiment has been described with reference to an example in which a groove-shaped continuous hole having a predetermined shape as shown in FIG. 5 is formed on the face of a tunnel, the present method is also applied to bench-cut excavation work of light construction. It goes without saying that you can do it.

[0019]

As is apparent from the above description, according to the present invention, a groove-shaped continuous hole for efficiently and highly accurately forming a free surface for excavating a face of a medium-hard rock tunnel or the like. It has the effect of being able to drill holes and realize efficient rock excavation work.

[Brief description of drawings]

FIG. 1 is a process flow chart showing a procedure of drilling work in an embodiment of a method of forming grooved continuous holes according to the present invention.

2A and 2B are a partial front view and a sectional view of the groove-shaped continuous hole shown in FIG. 1D in an enlarged manner.

FIG. 3 is a partial cross-sectional view showing an example of a core portion remaining in the annular bit.

FIG. 4 is a partial perspective view showing an example of an annular bit used in an embodiment of the present invention.

FIG. 5 is a schematic explanatory view showing an example of a pattern for forming a free surface on the face of the upper half of the tunnel.

FIG. 6 is an explanatory view showing an example of a conventional drilling device for forming grooved continuous holes.

[Explanation of symbols]

 1 Tunnel Face 1A Core 5 Groove-like Continuous Hole 10 Excavator 13 Drill 16 Casing Rod 20 Annular Bit D Drilling Diameter

Claims (2)

[Claims] 1. An annular hole is formed on a rock surface by the operation of an annular drilling means mounted on an excavator, and at the same time,
While controlling the drilling direction of the drilling means using the core portion which is cantilevered and remains in the bedrock as a guide core, a predetermined overlapping portion with the annular hole is provided at a position adjacent to the guide core. By moving the boring means so as to have it, the annular core is sequentially formed while the guide core remains formed in the bedrock, and a continuous groove-shaped portion is formed. Forming method. 2. A plurality of the drilling means are arranged in parallel at a predetermined interval so as to face the face of the face, and at the same time, a plurality of annular holes are formed, and the annular holes are made continuous to form a groove shape. A method for forming a groove-shaped continuous hole, characterized in that a portion is formed.