JP2006348638A - Excavating and jacking method and excavator for use in the method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance whole excavation efficiency by precedently excavating a small-diameter hole ahead of a cutting face and accelerating the release of stress of ground itself. <P>SOLUTION: In this excavating and jacking method, a jacking pipe is connected to a back end of the excavator 1, and embedded into an excavated hole while the ground is excavated by the excavator 1 in such a manner that the jacking pipe is pushed from a rear side. A central section of the cutting face to be excavated is precedently excavated long ahead of the cutting face by a small-diameter excavating bit 7; subsequently, the whole of the cutting face is regularly excavated by the excavator 1; the next precedent excavation is performed after the regular excavation is continuously performed until the length of the precedently-excavated hole Sa with a small diameter reaches a predetermined length or the hole Sa is put into a partially left state; and the excavation is performed by alternately repeating the precedent excavation and the regular excavation. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a technique for constructing a pipeline on a hard ground such as a rock.

Conventionally, in the tunnel construction method and the propulsion method, when rock excavation is performed, a roller bit or the like is disposed on the front surface of the excavator to cut the entire cross section at once. In that case, roller bits, etc. arranged on the cutter face of the entire surface tend to be difficult to cut in a uniform state of the bedrock etc. due to the difference in peripheral speed between the outermost periphery and the inner periphery, etc. It is in. In particular, in the construction of pipelines in bedrock soil exceeding 100 MPa, the excavation speed is generally extremely low, which causes a big problem in economy and construction period.
JP 2004-360179 A

  The problem to be solved by the present invention is to solve these conventional problems, and make a small-diameter hole in the center of the face in advance to promote stress release of the ground itself and improve the excavation efficiency. An object of the present invention is to provide an excavation propulsion method and an excavator used therefor.

The configuration of the present invention that solves this problem is as follows.
1) In the excavation propulsion method in which a propelling pipe is connected to the rear end of the excavator and the propelling pipe is pushed from behind and excavating the ground with the excavating machine, the propelling pipe is embedded in the central part of the face to be excavated. Is drilled long ahead of the face with a small-diameter excavation bit, and then the main face is excavated with the advancing machine, and the small-diameter hole drilled by the preceding excavation has a predetermined length or a part. Drilling propulsion method 2) The excavation length of the preceding excavation is characterized in that the next leading excavation is continued until the remaining state is reached, and the preceding excavation and the main excavation are repeated alternately. The excavation propulsion method 3) according to the above 1), wherein the excavation length of the main excavation is 3 to 5 times the excavation diameter and the excavation length of the main excavation is 1.5 to 2.5 times the excavation diameter of the main excavation. The excavator used for the excavation propulsion method according to either 1) or 2) The excavator is attached to the tip of a long rod, and the rod can be moved forward and backward so that the excavation bit can protrude forward from the excavation part through the inside of the excavator. Is installed at the center of the excavator, and the rod is provided so as to be able to advance and retreat inside the earth removal pipe. 5) The excavator is attached to the rear part of the rod, and the rack and teeth are located behind the excavator. The excavator according to the above 3) or 4) is provided with a driving gear to be engaged, and the rod can be moved forward and backward by moving the rack back and forth with the driving gear.

  According to the present invention, since the ground position of the portion where the peripheral speed is low according to the conventional example is pre-excavated to a small diameter by the excavation bit, the ground around the small-diameter hole of the pre-excavation is cracked to release the initial stress of the ground. As a result, the subsequent excavation and pipeline construction progress can be improved because it becomes easier to perform the main excavation by the excavator thereafter.

  In the present invention, the excavation length of the previous excavation is about 3 to 5 times the excavation diameter of the main excavation, and the excavation length of the main excavation is 1.5 to 2.5 times the excavation diameter of the main excavation (half of the excavation diameter). Length) is practical. The excavator is provided with a discharge pipe in the center so that a rod for advance excavation can be advanced and retracted in the discharge pipe. Embodiments of the present invention will be specifically described below with reference to the drawings.

  The embodiment shown in FIGS. 1 to 4 is an example in which the present invention is applied to excavation of a rock mass. FIG. 1 is an explanatory view of an excavating machine according to an embodiment, FIG. 2 is an explanatory view of a rod advance / retreat drive device according to the embodiment, FIG. 3 is an explanatory view showing holding of the rod in the earth discharging pipe of the embodiment, and FIG. It is explanatory drawing of this excavation propulsion construction method.

  In the figure, 1 is an excavator, 2 is a skin plate, 2a is a jack, 3 is an excavating blade, 4 is a motor, 5 is a soil pipe, 6 is a rod, 7 is an excavating bit, 8 is a rack, 8a is a support frame, 9 Is a forward / backward drive device, 9a is a pinion gear, 10 is a roller, 11 is a support, 12 is a roller, 13 is a swivel, 14 is a hydraulic jack, 15 is a water stop device, G is a bedrock, Ga is excavated sediment, S is a hole , Sa is a small diameter drilling hole, and T is a starting base.

  As shown in FIGS. 1 to 3, the excavator 1 according to the present embodiment has a plurality of excavating blades 3 that are rotated by a motor 4 attached to the front surface of a steel skin plate 2 and is surrounded by the excavating blades 3. The earth removal pipe 5 for taking in the excavated earth and sand Ga is attached to the inside of the skin plate 2 along the longitudinal direction.

  A long rod 6 having a drill bit 7 smaller in diameter than the drilling diameter of the drilling blade 3 is disposed through the earth discharge pipe 5, and a support frame 8 a having a rack 8 below is attached to the rear of the rod 6. An advancing / retracting drive device 9 having a pinion gear 9a driven by a motor that is not connected is disposed below the support frame 8a to mesh the rack 8 and the pinion gear 9a, and the upper portion of the support frame 8a is guided by a roller 10.

  In the earth removal pipe 5, a support 11 that supports the rod 6 at the center of the earth removal pipe 5 is disposed so as to be movable in the earth removal pipe 5 by a roller 12, and the rod 6 is supported by a swivel 13, and both sides of the support 11 are provided. The support position is fixed by press-contacting the inner surface of the soil discharge pipe 5 with a hydraulic jack 14 provided so that the rod 6 can be supported at a fixed position during excavation.

  In this embodiment, the excavator 1 is placed on a starting stand (not shown) at the starting base T, the propulsion pipe is connected to the rear end thereof, and the propulsion pipe is pushed in the excavating direction from behind by a pressing device. Mirror cut as shown in. Next, as shown in FIG. 4 (b), the advance / retreat drive device 9 is operated to advance the rod 6 while rotating, and the rock G is preliminarily excavated to a small diameter with the excavation bit 7 at the tip while pouring water through the rod 6. Drill a hole to a distance of about 4 times the excavating diameter of the excavating blade 3. The excavated earth and sand Ga at the time of drilling is taken in through the drainage pipe 5 together with fresh water.

  Next, as shown in FIG. 4 (c), the rod 6 is moved backward from the end of the soil discharge pipe 5, and the propelling pipe is pushed in the direction of excavation from the rear by a pressing device (not shown) of the starting base T to excavate the excavating machine 1 3, the rock G is excavated along the small-diameter hole Sa up to a distance ½ of the small-diameter hole Sa. At this time, a crack occurs in the outer peripheral portion of the small-diameter hole Sa, the initial stress is released and it is easy to be crushed, and the main excavation is performed quickly with a low load. Thereafter, the propulsion pipe is buried in the ground while digging by repeating the steps of FIGS. 4B and 4C.

  According to the present embodiment, since the position of the rock mass G at the portion where the peripheral speed is low according to the conventional example was previously excavated to a small diameter by the excavation bit 7, an initial stress of the rock mass G was generated by causing a crack at the outer peripheral position of the small diameter drilling hole Sa. The crushing by the excavating blade 3 can be easily performed quickly with a low load, and the progress of the final excavation / pipe construction can be improved.

  The excavation propulsion method of the present invention and the excavator used therefor are mainly useful for excavation of hard geology such as bedrock, but can also be applied to excavation of ground containing boulders or concrete galley left underground. In some cases, excavation can be performed in a short time with a lower load.

It is explanatory drawing of the excavation machine of an Example. It is explanatory drawing of the advancing / retreating drive apparatus of the rod of an Example. It is explanatory drawing which shows holding | maintenance of the rod in the earth discharge pipe of an Example. It is explanatory drawing of the excavation promotion construction method of an Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Excavator 2 Skin plate 2a Jack 3 Excavating blade 4 Motor 5 Exhaust pipe 6 Rod 7 Excavation bit 8 Rack 8a Support frame 9 Advance / retreat drive 9a Pinion gear 10 Roller 11 Support body 12 Roller 13 Swivel 14 Hydraulic jack 15 Rock stop G Rock Ga drilling earth and sand S drilling hole Sa small diameter drilling hole T start base

Claims (5)

  In the excavation propulsion method, where the propulsion pipe is connected to the rear end of the excavator and the propulsion pipe is pushed from behind and the ground is excavated with the excavator, the propelling pipe is embedded in the drilling propulsion method. The excavation bit was used to make a long excavation ahead of the face, and then the entire face was excavated with a digging machine, and the small-diameter drilled hole with the main excavation had a predetermined length or a part left. The excavation propulsion method is characterized in that the next preceding excavation is continued until the state is reached, and the preceding excavation and the main excavation are alternately repeated.   The excavation length of the preceding excavation is 3 to 5 times the excavation diameter of the main excavation, and the excavation length of the subsequent excavation is 1.5 to 2.5 times the excavation diameter of the main excavation. Drilling propulsion method.   The excavator used in the excavation propulsion method according to claim 1 or 2, wherein the excavation bit is attached to a tip of a long rod, and the excavation bit protrudes forward from the excavation part through the excavator. An excavator that can be moved forward and backward as possible.   The excavator according to claim 3, wherein a soil discharge pipe for discharging the excavated earth and sand is disposed in a central portion of the excavator and the rod is provided so as to be able to advance and retreat inside the soil discharge pipe.   The excavator according to claim 3 or 4, wherein a rack is attached to a rear portion of the rod, a drive gear that meshes with the rack is provided at an inner rear side of the excavator, and the rod can be moved forward and backward by moving the rack back and forth with the drive gear. .

Images