JPH11256970A - Excavating method for hard rock bed and its device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology for accurately smoothly carrying out a long and large bore drilling and excavating in a hard rock bed in a short term according to a design. SOLUTION: In a case of excavating a fixed large bore and long drilled hole in a superhard rock bed 6, an auxiliary excavating device 4 is inserted in a casing 1 through a wire 7 in a suspended state by a crawler crane 3, and an air hammer 17 at its tip is steadily set on the rock bed 6 being an excavation objective face, and the wire 7 is loosened to expand a pressure contact mechanism acting as a chuck mechanism, and its shoe is pressure-clampedly fixed to the inside face of the casing 1 and united, and the torque and pressing force caused by a totally rotary type all casing excavator 2 is given to the casing 1. Thus the torque and pressing force are given to the auxiliary excavating device 4 through the casing 1, and an impact crushing and a crushing fatigue are given to the excavation objective rock bed 6 on the inside at the tip of the casing 1 by the air hammer 17 for carrying out an excavation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The disclosed technology belongs to the technical field of excavation for installing a casing for a super-hard rock or the like under a normal ground.

[0002]

2. Description of the Related Art In recent years, with the rise of industry, structures requiring high social capital, such as high-rise buildings, expressways and marine bridges, are pan-topographic nationwide regardless of terrain and terrain. With the increase in coverage and hugeness, the construction of these industrial structures requires long, large-diameter boreholes for the foundations, but these boreholes are often located in mountainous forests and are long and complex. In Japan with special terrain conditions close to a natural coastline, drilling of ordinary soft ground has reached its limit, and it is necessary to superstructure the structure and install it on a pan-terrain basis From the point of view, in the conventional mode, there is a tendency to increase the number of construction sites that require excavation of hard rock such as ultra-hard rock which requires blasting, and it is estimated that the tendency will be remarkable in the future.

[0003] The need for excavation of such hard rock has been pressed, and various excavation techniques have been researched and developed to be put into practical use. Excavation methods are broadly classified, and such excavation methods include the following techniques.

That is, first, an auger screw excavation method is used, in which a hard bit is cut and excavated by rotating and pressing a tip bit having a special cutting edge, and excavated shear generated is discharged through the auger screw. Is to do so.

[0005] Next, in the rotary excavation method, cutting is performed by rotatingly press-fitting a tip bit having a special cutting edge into the hard rock, and excavated shear generated by the cutting is discharged by a muddy water reverse circulation system. In the case where the hard rock is a medium hard rock or a super hard rock which cannot be excavated, it is a method of performing impact crushing by dropping a chisel.

[0006] Next, in the chisel falling type percussion excavation method, the rock is crushed by the impact of the chisel and the casing pipe is oscillated in the circumferential direction and is pressed into the rock to protect the hole wall. This is a method of excavating while performing.

[0007] Next, an air hammer hitting percussion excavation method is a method of crushing the rock by the impact of a chisel, and a continuous hitting of a hammer inserted with a carbide bit using compressed air as a power source. This is an excavation method that has two types of drilling methods.

In the last casing rotary excavation method, the casing in which the excavation bit having a special cutting edge is fixed at the tip is rotated in the circumferential direction in the same manner as the above-described method, and press-fitting cutting is performed on the rock to protect the hole wall. This is a construction method in which excavation is promoted, and at the same time, the rock inside the casing is crushed by the fall of the chisel at the same time, and the inside of the casing is excavated by a hammer grab.

However, in the above-mentioned conventional excavation methods, a long and large-diameter excavation method corresponding to a hard rock such as an ultra-hard one has not yet been completely adopted and has not been technically established. Things.

[0010] That is, in the auger screw excavation method, in the case where it is difficult to perform excavation relying only on the cutting function by rotary press-fitting, impact excavation by dropping a chisel can be used as an auxiliary method, At that time, pull out the excavating mechanism for the entire length of excavation
The work is then extremely cumbersome to follow the process of reinserting the excavating mechanism after the excavation process has been completed, and, in addition to being inefficient, relying on the rotary pressure input for the excavating force, Due to the mechanical limitation of using a suspended auger machine as its supply source, it is difficult to apply to large-diameter excavation exceeding 1500 mm, and the rotary excavation method also employs cutting as the principle of excavation. Therefore, there is a drawback that it is difficult to use a blow method or the like in combination due to the equipment configuration.Therefore, so-called high-speed construction as in the case of using the blow crushing method or the same method cannot be expected, and the construction period is unnecessarily long. There is a bottleneck.

As described above, the excavation method has an unfavorable point that the excavation efficiency is significantly reduced when a hard rock or the like is used as an excavated rock.

The chisel falling percussion excavation method is a method of hitting and crushing the entire cross section of the rock due to the impact of the falling of the chisel, and is applicable to large-diameter excavation of soft rock or the like. There are drawbacks that cannot be applied to the excavation of rocks with extremely high hardness such as hard rocks, and there is also the disadvantage that it is difficult to press-fit casing pipes that have only a cutting function into the bedrock layer as a press-fit assist. .

[0013] The air hammer hitting percussion excavation method is capable of stably excavating a super-hard rock mass. However, when the entire surface of the excavation is to be drilled, a long and large-diameter excavation method is used. At times, a large amount of compressed air is required, which leads to high costs in terms of power costs and the like, and its application is economically disadvantageous.

The last casing rotary excavation method is the above-mentioned cutting and press-fitting cutting, a compromise between the press-fitting method and the hitting method. The casing with the bit fixed at the tip is rotationally press-fitted, and while cutting is promoted, while excavating inside the casing through impact crushing with a chisel or hammer grab, it can also be applied to hard rock excavation. When digging a super-hard rock mass exceeding the cutting ability of the casing, the digging efficiency is remarkably reduced, thereby significantly increasing the length of the construction period and causing various inconveniences in practice.

Therefore, when excavating hard rock which is difficult to hit and crush by a chisel by the casing rotary excavation method, a rotary mechanism for an air hammer such as a rotary table is provided on a full-rotation type all casing excavator, and a crawler is provided. The air hammer is suspended by a crane or the like, and a rotary impact excavation is performed by an air hammer in a form of being inserted into a rotating mechanism such as the rotary table.
By performing a plurality of pre-drilling with a small diameter on the inner circumference of the casing, a chisel, and assisting excavation in the casing by a hammer grab, it is possible to adopt a mode of excavating in a predetermined manner, but the plurality of drilled holes It is unavoidable to extend the construction period due to the complexity of moving the air hammer rotation mechanism to perform the work, and if the rock is to be crushed near the bottom of the long and large diameter hole, Not only the initial cost, but also the need for an extended drill rod connecting the air hammer rotation mechanism and the drilling machine, resulting in an increase in the weight of the drilling device and an increase in the size of the attached crawler crane However, there is a disadvantage that running costs cannot be avoided.

[0016] In the case of the excavation by the casing rotary excavation method, even if it becomes possible to dig inside by drilling holes in the casing, the hardness of the surface to be cut by the casing is not reduced, and the excavation bit at the tip of the casing is not reduced. Is severely worn, thereby causing troubles such as breakage of the drill bit, which leads to a decrease in construction efficiency. As a result, a casing lock phenomenon due to so-called jamming occurs, resulting in a decrease in operation efficiency and inability to construct. However, there is a problem that the point of occurrence has not been solved yet.

[0017]

In order to cope with these problems, in recent years, a full-rotation type all-casing excavator has been used to press-fit a casing in which an air hammer is disposed in a ring shape at the tip thereof by the full-rotation all-casing excavator. A method of excavating hard rock that combines the impact crushing capacity of an air hammer with the large-diameter excavating ability of an all-rotation all-casing excavator has been developed, but a method of excavating rock has been developed. ， Effective for excavation of large diameter, but cost is required because large-scale machine plant is required for complex alternate layer with hard rock where ordinary soft ground intervenes, which does not require impact crushing. However, there is an inconvenience that the utility is poor due to disadvantages such as an enormous increase in size.

Accordingly, as described above, it is now possible to excavate a long, large-diameter ultra-hard rock mass,
In addition, an inexpensive and highly efficient excavation construction technology has not been deliberately established, and the emergence of such excavation technology is strongly desired.

[0019]

SUMMARY OF THE INVENTION The object of the invention of this application is to solve the problem that the conventional method of auger screw excavation to casing rotary excavation from the above-mentioned 1 to excavation could not be performed as designed. And excavation of long and large-diameter excavations on an alternate layer with soft rock including the hard rock can be performed quickly, accurately as designed, and at low cost. An object of the present invention is to provide an excellent method for excavating hard rock, which is beneficial to the field of application of foundation construction work technology in industry, and an apparatus used directly in the method.

[0020]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a construction of the invention of the present application for solving the above-mentioned problems is provided in a casing in which a cutter bit for cutting is fixed at a tip end. While rotating and press-fitting into the target hard rock through a full-rotation all-casing excavator, the rock is cut and the casing is built in a drilling hole, and the casing is excavated while protecting the hole wall with the casing. A hard rock excavation method, wherein an auxiliary excavator having an air hammer is inserted into the casing and fixed to a rock excavation surface prior to cutting and excavation by the casing, and a blow crushing action is performed on the excavated rock inside the casing. In this way, it is necessary to perform a considerable amount of excavation, and at the same time, generate impact fatigue on the remaining target rock to perform auxiliary excavation inside the casing. When the auxiliary excavation is performed by the means, the auxiliary excavation device is pressed against the lower inner surface of the casing to perform the auxiliary excavation. The process may be performed by applying a rotating force, and then the process of performing the auxiliary excavation prior to the cutting excavation by the casing and performing the process of removing the auxiliary excavation debris by a hammer grab may be performed in a cycle. Thus, as an apparatus directly used for the hard rock drilling method, an auxiliary drilling apparatus inserted and installed in the casing has a crimping mechanism for the casing and a drill housing equipped with an air hammer below the crimping mechanism. The additional crimping mechanism is disposed on the auxiliary drilling device. To placed in the panel of the excavating surface, together, so as to be adapted to integrate the casings and automatically pressed against the inner surface of the casing, further,
Technical means is provided in which a hose for supplying compressed air to the air hammer is loosely inserted into the all-rotation all-casing excavator and connected to a drill housing.

[0021]

In the construction of the above-mentioned means, first, when a predetermined hard rock is excavated, a normal soft ground on the upper part of the hard rock or, if there is a soft rock, a casing is formed and a full-rotation all casing excavator is used. Performing a stable cutting excavation work with vertical accuracy as designed on the soft ground through a drill bit at the tip of the casing in a predetermined manner, and the drill bit at the tip of the casing has a hardness that cannot be excavated by the above-described excavator. When the hard or ultra-hard rock mass is reached, the casing is pulled up by a predetermined stroke, and an auxiliary drilling device having an air hammer is inserted into the casing via a crawler crane or the like, and the air hammer of the drill housing at the tip of the device is inserted into the drilling surface. A button bit or the like of an air hammer that has been reached and fixed circumferentially to the lower part of the drill housing The compressor is attached to the excavation surface and compressed air is supplied from a compressor attached to the crawler crane to the drill housing via the auxiliary drilling device via the air hose and the auxiliary drilling device, and is pressure-fed to the button bit of the air hammer to be in an operating state. In the ring-shaped excavation and cutting portion where the excavation bit is faced, and the entire surface of the excavation inside the portion is subjected to impact crushing action, causing fatigue in the cutting ground and exerting auxiliary excavation. Of the air hammer to effectively perform the crushing action on the inner surface of the casing adjacent to the inner surface of the casing,
When the predetermined crushing is performed, the auxiliary digging device is pulled up, a hammer grab for digging is inserted, and the crushed debris hit and crushed by the air housing is discharged. The casing, which had been turned, was again press-fitted by a full-rotation type all-casing excavator, and the cutting by the rotation was continued through the cutting of the rock subjected to the crushing action, and the excavation was continued. Excavation is performed by impact crushing via an air hammer by the preceding auxiliary drilling equipment, so the crushed surface is affected by impact fatigue, so excavation is performed smoothly, casing lock phenomenon due to jamming does not occur, Excavation was performed as designed, and all-rotation type all-casing construction for conventional hard rock excavation and air hammer combined use And, without long interruptions due to a tooling change, such as the installation, smooth construction work progresses, good operating efficiency, auxiliary excavation casing integral with the rotational force due to all rotary all casing excavator, and,
Since the pressing force is applied, the operation of the excavation plant using a crawler crane or the like can be freely performed, and large-diameter, long excavation can be performed on a hard rock having a hardness equal to or higher than that of a medium hard rock or on an alternate layer containing the rock. It is designed to be performed with optimal efficiency as designed.

Incidentally, the above-mentioned measures for preventing the occurrence of the jamming device can be performed by excavating at a stable speed without stagnation and shortening the time for stopping the rotation of the casing. Fine sand,
It is based on the logic that the risk of clogging (jamming) between the casing and the hole wall such as fine slime can be reduced.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following is a description of embodiments of the present invention as embodiments of the present invention, with reference to the accompanying drawings.

In the embodiment shown in FIG. 1, A is a drilling plant used for hard rock drilling work of the invention of the present application,
The plant A includes a casing 1 having a predetermined large diameter, a full-rotation all-casing excavator 2 having a known circumference, and a hammer grab 2 ′.
(The illustrated embodiment is an embodiment in which the chisel (not shown) is carried in a predetermined position and a crawler crane 3 for carrying in a predetermined manner. An auxiliary drilling device 4 that can be inserted and pulled up in the casing 1 is provided.
In the state where the casing 1 is pulled up, the casing 1 is rotationally cut by the all-rotation all-casing excavator 2 to cut and excavate the upper ordinary ground 5 (the ground 5 including the alternating ground of soft rock) as designed vertically. When excavating a hard rock 6 such as a super hard rock below the ordinary ground 5, the excavation is performed via the auxiliary excavator 4.

The auxiliary excavator 4 is detachably inserted into the casing 1 from the crawler crane 3 via the wire 7 and the hook 8, and a compressor (not shown) provided in the crawler crane 3 is connected to the auxiliary excavator 4. As shown in FIG. 2, compressed air is loosely inserted into the all-rotation type all-casing excavator 2 through the air hose 9, passes through the air swivel 10, passes through the auxiliary excavator 4, and then, as shown in FIG. ), A mounting bracket on a lower circumference of the rod housing 14 which is fed to a drill housing 14 connected to the lower side via a 13 and precedes a drill bit 15 provided at the tip of the casing 1. Button bits 17, 17... As air hammers circumferentially arranged at predetermined intervals at 16 (in FIGS. 1 and 2, for convenience of illustration, a pair of button bits 7 and 17), the hammer grab 2 ′ and the crushing portion 27 (before the cutting by the cutting bit 15 of the casing 1) before the cutting of the casing 1 by the cutting bit 15 when excavating the hard rock 6 where the excavation by the chisel becomes impossible. FIG. 3) is hit and crushed in a ring shape. At this time, the cutting fatigue is spread to the cutting and crushing portion 29 of the drill bit 15 close to the outer periphery of the crushing portion 27 and the rock portion 28 remaining on the inner periphery. The cutting and crushing by the drill bit 15, the auxiliary crushing and excavating work of the rock by the hammer grab 2 'and the chisel set in the casing 1, and the removal of the crushed debris can be smoothly performed.

As shown in FIG. 2, the auxiliary drilling device 4 connects the drill housing 14 to the upper cylindrical sleeve 18 through the flange 12 by the rod 13 thereof. A center rod 19 (20) that moves up and down via a spring 21 as a telescopic mechanism is inserted between the flanges so as to freely move up and down. A weight 22 is provided above the sleeve of the center rod 19 (20). Bracket 24 provided
A bendable link 2 is provided between the bracket and the bracket 24 'of the shoe 25 as a crimping mechanism for the inner wall of the casing 1.
The auxiliary excavator 4 is provided with the crawler crane 3 to move the wire 7
The clearance 26 between the shoe 25 and the casing 1 is balanced with the weight of the auxiliary digging device 4 and the suspension force of the wire 7 so that the inside of the casing 1 can be freely moved up and down in a loosely inserted state through FIG. As shown in the right cross section, it is formed in a predetermined manner so that the loose insertion state can be maintained.

When the button bit 17, 17 as an air hammer at the tip of the drill housing 14 is loosely inserted into the casing 1 and lands on the excavated surface of the rock at the tip of the casing 1, the wire becomes stationary. 7 is loosened, and the weights 22 and the springs 21 engage with each other, so that the links 23 and 2 of the crimping mechanism 11 serving as the chuck mechanism are loosened.
As shown in the left sectional view of FIG. 2, the clearance 2 between the casing 1 and
6, the shoe 25 is crimped on the inner surface of the casing 1 with the shoe 25, and the casing 1 and the auxiliary excavator 4
Are integrally connected and fixed. Therefore, when the rotary press-fitting action is given to the all-rotation all-casing excavator 2 in this state, the casing 1 is turned into a rotary press-fit state, and the casing 1 and the shoe 5 are interposed. The drill housing 14 of the integrated auxiliary drilling device 4 is also made to be able to rotate and evolve integrally, so that the button bits 17, 17,... The impacting and crushing action is exerted on the cutting portion 29 of the drill bit 15 of the casing 1 on the bedrock surface and the adjacent portion 27 inside the cutting portion 29, and the fatigue caused by the impact crushing is transmitted to the inner portion 28 of the adjacent portion 27, and the hammer grab in a later process is performed. In addition to smooth crushing and debris discharge by 2 ', drilling work by the drilling plant A can be performed quickly and without stagnation. The appearance of the casing lock state due to the flow of groundwater inside and outside the casing 1 and fine sand, and jamming generated between the outer circumference of the casing 1 and the inner circumference of the excavation hole due to the presence of fine granules of rock excavation debris. It is designed to be avoided.

In the drilling pipe A having the above structure, first,
When excavating the ground on the general ground 5, first, the crawler crane 3 is loaded and set in a predetermined manner, and the all-rotation all-casing excavator 2 via the wire 7 and
The casing 1, the hammer grab 2 ′, and the chisel (not shown) are carried into a predetermined position, and only the casing 1 is passed through the all-rotation all-casing excavator 2 without inserting the auxiliary excavator 4 into the casing 1. When the excavation is performed smoothly on the normal ground 5 vertically and the excavation bit 15 at the tip of the excavator abuts against the hard rock 6, the excavation resistance is measured in a predetermined manner and only the casing 1 by the all-rotation all-casing excavator 2 is used. The excavation by cutting is stopped. Then, the auxiliary excavator 4 is suspended and inserted into the casing 1 through the crawler crane 3 by the wire 7 through the hook 8 to be lowered.

That is, at the stage when the ground 5 is cut and excavated with a predetermined stroke, the hammer grab 2 ′ or a chisel (not shown) is inserted into the casing 1 via the crawler crane 3 to discharge the excavated debris to a predetermined extent. The cutting and excavation of the casing 1 is performed again, and the above process is repeated. When the excavation bit 15 at the tip of the casing 1 reaches the super hard rock 6 having a hardness equal to or higher than the medium hard rock, the excavation resistance is detected in a predetermined manner, and the full rotation type is detected. All casing Excavator 2 casing 1
Is stopped, and the auxiliary excavator 4 is inserted into the casing 1 by the crawler crane 3 via the wire 7 while being suspended from the wire 7.

In this state, the suspension force of the wire 7 and the total weight of the auxiliary excavator 4 are balanced, and the shoe 25 of the crimping mechanism 11 as a chucking mechanism is
Due to the retracted state of 23, 23, shoe 25 is
The auxiliary drilling device 4 is smoothly inserted into the casing 1 and lowered so as to form the clearance 26 with the inner surface of the rock drill 6, and each button bit 17 as an air hammer of the drill housing 14 is formed inside the casing 1 of the rock 6. Is set to the stationary state on the entire cross section of the rock 6.

At a predetermined timing before and after this process, the level of the excavation bit 15 at the tip of the casing 1 is raised so as to be higher by a predetermined stroke than the position of the button bit 17 as an air hammer.

When the rotary pressing force is applied to the casing 1 from the all-rotating all-casing excavator 2, the casing 1 receives a rotational force and a pressure input from the all-rotating all-casing excavating machine 2 through a cutting bit 15 at the tip thereof. Then, cutting and excavation of the ground 5 is started vertically.

Of course, in this process, the outer diameter of the drill housing 14 is made smaller than the inner diameter of the casing 1 in advance, so that the auxiliary drilling device 4 is smoothly inserted into the casing 1. At the end of the insertion process, the button bit 17 of the air hammer of the drill housing 14 is placed on the excavation surface of the hard or super-hard rock 6 having a hardness higher than the hardness.

During this time, the casing 1 is raised by a predetermined stroke via the all-rotation all-casing excavator 2 at a predetermined timing, and the auxiliary excavator 4 performs auxiliary excavation by impact crushing prior to the subsequent cutting excavation by the casing 1. To do.

When the setting of the auxiliary excavator 4 in the pre-excavation posture state with respect to the casing 1 with respect to the predetermined super-hard rock 6 is completed in this way, the rotary press-fitting action is applied to the casing 1 via the all-rotation all-casing excavator 2. Give.

When the button bit 17 as an air hammer at the tip of the drill housing 14 of the auxiliary drilling device 4 is fixed on the excavation surface of the super-hard rock 6, the wire 7 is loosened. As a result, each link 23 is contracted to bring the bracket 24 'closer to the inner surface of the casing 1, where the crimping mechanism 11 as a chucking mechanism uses the shoe 25 to crimp the inner surface of the casing 1. In this case, the pressing state appears by the action of the weight 22, and the auxiliary excavator 4 is integrally provided with the casing 1 and the rotary pressing force by the all-rotation all-casing excavator 2.

The crimping mechanism 11 functions as a chuck mechanism, and when the weight of the wire 7 and the auxiliary digging device 4 is balanced, as shown in the right half section of FIG. The bracket 25 'is retracted toward the center rod 19, and the shoe 25 and the casing 1 are moved.
A clearance 26 is formed between the auxiliary excavator 4 and the casing 1 so that the auxiliary excavator 4 can be freely inserted into the casing 1.
When the button bit 17 as an air hammer of the drill housing 14 is fixed to the excavation surface of the rock 6, the wire 7 is loosened, and as shown in the left half section of FIG. As a result, each link 26 expands by a predetermined angle with respect to the sleeve 18 to form a bracket 24 ′ to approach the inner surface of the casing 1,
The shoe 25 of the crimping mechanism 11 as a chuck mechanism is crimped to the inner surface of the casing 1 to maintain the pressed state by the load of the weight 22, and the all-rotation all-casing excavator 2 is mounted on the excavator 4 via the casing 1. The rotational force and the pressing force are applied integrally.

When a rotary pressing force is applied to the all-rotation all-casing excavator 2 in this state, the auxiliary excavating device 4 is provided with a rotational force and a pressing force integrally with the casing 1 so as to be press-bonded as a chucking mechanism. The button bit 17, which is integrally provided through the mechanism 11 and serves as an air hammer,
17 apply a predetermined impact force to the adjacent portion 27 inside the casing 1 as shown in FIGS.
The rock 6 is subjected to impact crushing and is excavated in a predetermined ring shape.

In the meantime, the cutting portion 29 of the cutting bit 15 of the casing 1 for performing cutting and excavation, and the cutting portion 29 of the ring-shaped striking and crushing portion fall down in the subsequent process due to the impact and crushing of the button bit 17. The fatigue caused by the impact crushing is applied to the inner portion 28 of the adjacent portion 27 so that the crushed waste is discharged in the subsequent process and the cutting and digging by the digging bit 15 is smoothly performed.

At the stage when the excavation by the preceding impact crushing by the excavator 4 has completed a predetermined stroke, the auxiliary excavator 4 is pulled out of the casing 1 via the wire 7 and a hammer grab 2 'for excavation or a chisel (not shown) Is inserted into the casing 1 and the crushed debris on the excavated surface of the rock 6 that has been hit and crushed by the button bit 17 as an air hammer is discharged in a predetermined manner, and the inside of the adjacent portion 27 of the ring-shaped digging and hitting crushing portion is also discharged. Crushing and excavation of the rock 6 which is easily broken by the fatigue of the part 28 is performed to discharge the crushed debris to the outside of the casing 1. When predetermined discharge is completed, the hammer grab 2 ′ and a chisel (not shown) are removed. Casing 1
It is taken out, the auxiliary drilling device 4 is inserted into the casing 1 again, and the button bit 17 is fixed on the entire cross section of the bedrock 6 from which the crushed debris has been discharged. The auxiliary excavator 4 is operated again by the casing 1 to perform excavation by impact crushing on the excavation surface of the rock 6, and the inner portion 28 of the adjacent portion 27 of the ring-shaped impact crusher and the excavation bit 15 Excavation is performed so that crushing fatigue is exerted on the cutting portion 29 and cutting and excavation by the casing 1 at the subsequent stage is smoothly performed.

In this process, in the digging operation by cutting the casing 1, the digging bit 1
Since the crushed debris of the super-hard rock 6 around the area 5 is eliminated, the excavation by impact crushing with the button bit 17 as the preceding air hammer and the fatigue spread due to the crushing affect the digging bit 15 of the casing 1. The jamming action by the fine crushed debris and the like does not reach the casing 1, so that the casing lock phenomenon does not occur, and the excavation by the smooth cutting of the casing 1 is performed vertically.

As a countermeasure to prevent the occurrence of the jamming, the excavation can be performed at a stable speed without stagnation as described above, and the time for stopping the rotation of the casing 1 is shortened. It is based on the logic that the risk of clogging (jamming) between the casing of fine sand and fine slime due to the inflow and the hole wall can be reduced.

When the excavation through the impact crushing of the entire cross section of the bedrock 6 inside the casing 1 of the auxiliary excavator 4 is completed as described above, the auxiliary excavator 4 is again connected to the wire via the crawler crane 3 as described above. 7 and pulled out of the casing 1, a chisel or a hammer glove 2 ′ (not shown) is hung by the wire 7, and is loosely inserted into the casing 1 to remove the casing 1.
The crushed debris hit and crushed by the button bit 17 is collected from the inner bottom and removed outside the casing 1, and the auxiliary drilling device 4 is inserted into the casing 1 again, and the button bit 17 as an air hammer of the drill housing 14 is provided. 17 ...
And the above-described process is repeated to excavate the hard super hard rock 6 more than the medium hard rock vertically.

The preceding excavation by the auxiliary excavator 4 and the subsequent excavation by cutting the casing 1 through the excavation bit 15 are performed by the button bit 17 due to the initial positional relationship between the two exposing strokes. Excavation via preceding impact crushing and excavation bit 15
The excavation by the cutting by the casing 1 through the above is always performed continuously through the same phase.

When the excavation at the predetermined depth is completed, the auxiliary excavator 4 and the casing 1 are pulled out and removed from the all-rotation type all-casing excavator 2, and finally, the crawler crane 3 is used to remove the auxiliary drilling device 4 and the casing 1. Is also removed and the construction is completed.

At this time, the hammer grab 2 'is of course removed for the next time.

It should be noted that the embodiments of the invention of this application are not limited to the above-described embodiment. For example, the construction method is as follows. Excavation is performed on the ordinary ground on the ultra-hard rock 6 and on the alternate ground 5 on the soft rock. In this case, various modes such as excavation using the auxiliary excavator 4 in addition to the cutting excavation by the casing 1 can be adopted.

It is of course possible to use a known chisel instead of the hammer glove 2 '.

[0049]

As described above, according to the invention of this application, basically, a long rock, a hard rock such as a soft rock, a medium hard rock, and an ultra hard rock,
When drilling through large-diameter excavation, not only is the suspension-type lightweight, and highly operable impact crushing and excavation of the ultra-hard rock mass by the impact crushing force of a button bit of an air hammer, etc. The fatigue caused by the impact crushing is applied to the entire surface of the target rock for cutting and excavation of the casing in the post-process and the entire cross-section of the target rock inside the casing from the target surface. Therefore, there is an excellent effect that the drilling with the casing can be smoothly performed, and the drilling with the predetermined large depth can be set as designed and the large-diameter drilling with the set large depth can be performed.

Moreover, there is an advantage that a heavy equipment plant having a full-rotation type all-casing excavator can be freely applied to excavation of a large-diameter and long hole in hard ground such as ultra-hard rock, which has been difficult in the past. Auxiliary drilling equipment can be inserted into the casing via wire suspension such as a crawler crane of the plant, and the crawler crane can be used to replace the auxiliary drilling equipment with minimum working time in accordance with changes in the target rock ground. In addition, replacement with a hammer grab or chisel, or setup change can be performed in a minimum time, so that there is also an effect that the construction efficiency is improved.

In the invention, since the auxiliary excavator inserted and installed in the casing has a crimping mechanism as a chuck mechanism for the inner surface of the casing, the auxiliary excavator is inserted into and removed from the casing by the chuck. The crimping mechanism of the mechanism is loosened to disengage the crimped state with respect to the casing, and as a result, insertion and removal can be performed freely, and in the crimped state, only the rotating action and the press-fitting action on the casing by the all-rotation all-casing excavator are applied to the casing. The auxiliary excavator, which is integrally crimped and tightened via the casing, is integrally provided with a rotary press-fitting action, and its air hammer is provided with a percussion crushing action on the entire cross section within the casing of the super-hard rock, and the subsequent casing is provided with An excellent effect that cutting and excavation can be performed smoothly is achieved.

Further, there is no need for an earth auger or a rotary table or the like, and there is no need for a rotating force supply device for a long drill rod or the like, and any rotational driving force transmitting device or pressing force transmitting device is separately provided. In addition, since the rotation of the air hammer of the auxiliary excavator and the pressing force can be applied with the all-rotation type all-casing excavator through the casing, the equipment cost is reduced and the weight is reduced, and the operability is improved. The standard selection of the crane bogie is not restricted by the type and weight of the auxiliary drilling equipment, etc., the equipment cost is reduced compared to the conventional air hammer excavation combined construction method, the construction is carried out at low cost, and the construction period An excellent effect of adding to the shortening is achieved.

Further, the long and large-diameter hard rock excavation can be smoothly performed without stagnation, so that the groundwater flow and fine sand, and the gap between the outer periphery of the casing and the inner periphery of the excavation hole caused by the presence of rock excavation debris can be obtained. Thus, the effect of suppressing the appearance of the casing rod state due to the jamming that occurs is produced.

As described above, in the conventional mode, for a super-hard rock having a hardness equal to or higher than that of a medium hard rock or an alternate layer containing them, a large diameter as designed vertically is used in the construction using a full-rotation all-casing excavator. , Although long drilling was not possible, drilling with the casing and digging inside the casing are possible, good drilling efficiency, avoiding unnecessary delays in the construction period, and smooth drilling as designed. There is an effect that pores are formed.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional schematic side view of a construction state according to an embodiment of the present invention.

FIG. 2 is a half cross-sectional side view of a casing and a supplementary excavating apparatus in a state where an air hammer is inserted into the casing and an air hammer is fixed to a bedrock.

FIG. 3 is a cross-sectional view of the construction, (a) is a plan sectional view including an air hammer of an auxiliary excavator, and (b) is a percussion crushing portion of the rock mass to be constructed by the air hammer and the percussion crushing. It is a plane sectional view of the influence part of fatigue fracture.

[Explanation of symbols]

 15 Cutter Bit for Cutting 1 Casing 6 Target Hard Rock 27, 28, 29 Remaining Target Rock 4 Auxiliary Drilling Device 2 Full-Rotation All-Cassing Excavator 2 'Hammer Grab A Device 17 Air Hammer (Button Bit) 14 Drill Housing 11 Crimping Mechanism (Chuck mechanism) 9 Hose 10 Air swivel 8 Hook

Claims (5)

[Claims] A casing having a cutter bit fixed at the tip thereof is rotatably pressed into a target hard rock through an all-rotating all-casing excavator, and the rock is cut to build the casing into a drilling hole. In a hard rock excavation method for excavating the inside of a casing with the casing while protecting the hole wall with the casing, an excavation device having an air hammer is inserted into the casing prior to the cutting excavation by the casing, and the excavation of the hard rock is performed. A hard rock excavation method characterized in that auxiliary excavation is performed by imposing a percussion excavation by an air hammer using the rotational force of the casing while being fixed on a surface. 2. An auxiliary excavator is pressed against an inner surface of a lower portion of a casing when performing the auxiliary excavation, and the auxiliary excavation is performed in an integrated state to cause fatigue in the cutting rock through the impact of the air hammer. The method according to claim 1, wherein auxiliary drilling is performed. 3. A casing in which a cutting cutter bit is fixed at the tip is rotary-pressed into a target hard rock through a full-rotation type all-casing excavator, and the rock is cut to build the casing into a drilling hole. In an apparatus used for a hard rock excavation method for excavating the inside of a casing while protecting the inside of the casing with a hole wall, an auxiliary excavating apparatus inserted and installed in the casing includes a crimping mechanism for the casing and air below the crimping mechanism. A hard rock drilling rig comprising a drill housing equipped with a hammer. 4. The crimping mechanism according to claim 3, wherein the crimping mechanism is disposed in the auxiliary excavator and automatically crimps to the inner surface of the casing when the crimping mechanism is fixed on the excavation surface of the hard rock. A hard rock drilling rig as described. 5. The hard rock drilling apparatus according to claim 3, wherein a hose for supplying compressed air to the air hammer is connected to the drill housing by loosely inserting the all-rotation type all-casing drilling machine.