JP2008038593A - Bore-increasing excavation method and bore-increasing excavation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bore-increasing excavation system wherein at least earth and soil produced by excavation can be taken into a casing or the bottom section of a preceding excavation hole, on the assumption of a construction method comprising a preceding excavation process and a bore-increasing excavation process of increasing the bore of the preceding hole to finish a shaft of a desired diameter. <P>SOLUTION: A preceding excavation hole H1 of a diameter D2 is drilled by turning a preceding excavation casing 1 to penetrate the ground. The bore-increasing excavation process succeeding the preceding excavation process comprises the step of turning bore-increasing excavating machine 5 to penetrate the preceding hole H1 for increasing the bore of the hole H1 to the diameter D3. A bore-increased excavation hole H2 thus obtained is used as a shaft. A gap A is positively kept between the diameter D1 of the casing 7 of the excavating machine 5 and the diameter D2 of the excavation hole H1 so that the earth and sand produced by bore-increasing excavation easily fall and can be taken into the bottom section side of the hole H1. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a method for expanding a diameter and a diameter expanding excavation system in the ground, and in particular, in the form of expanding the bottom or diameter of a caisson's cutting edge when constructing a shaft by press-fitting and sinking a caisson (including a PC well). The present invention relates to a diameter expansion drilling method and a diameter expansion drilling system suitable for excavation.

  The Ministry of Land, Infrastructure, Transport and Tourism has been enacting the Act on Special Measures for Public Use of Deep Underground on April 1, 2001 for the purpose of effective use of deep underground.

  The deep underground in the Special Measures Law refers to the underground at least 40 meters deep, which increases the need for construction of a vertical shaft that connects the deep underground space and the ground. Various construction methods have been developed with the goal of technology that can be built deeper and more safely. In many cases, these shafts are constructed by the caisson construction method.

  On the other hand, when trying to inject and sink caisson while excavating hard ground (pointed to soft rock and medium hard rock), excavation under the cutting edge of caisson is not possible with excavation with existing equipment such as hammer grabs. For example, as described in Patent Documents 1 to 4, various diameter expanding excavators that enable excavation under the caisson edge have been proposed.

  These drilling devices are large-diameter drilling devices in which drilling blades are attached to the outer periphery of the casing pipe, and the earth and sand excavated by the drilling blades are taken into the casing pipe and then discharged by a grab bucket or the like. Yes.

More specifically, in the conventional techniques represented by the above-described Patent Documents 1 to 4, a rotary push-in device that holds the casing and pushes it into the ground while rotating the casing, and the casing are attached to the casing. A drilling blade is provided on the expanded drilling blade, and a hard ground can be drilled by pushing the casing while rotating the casing with the rotary pushing device. In this case, the excavated earth and sand is taken into the casing from the earth and sand intake opening formed around the casing, and the earth and sand taken in the casing is grabbed with a hammer grab or a grab bucket and discharged. ing.
Japanese Patent No. 2674731 Japanese Patent No. 3031876 Japanese Patent Laid-Open No. 2005-98048 JP 2004-176530 A

  However, in the various conventional techniques as described above, when the ground to be excavated is hard ground and the geology is a viscous soil system, soil and water are agitated by the excavating blade after excavation. It changes to mud with high tackiness (so-called sludge phenomenon). The sludged sediment will stay near the intersection of the enlarged digging blade and casing (near the root of the enlarged digging blade relative to the casing), or it will become compacted and adhere to the entire drill wing due to the retention. become. As a result, the efficiency of taking excavated sediment into the casing deteriorates, and the gripping capacity of the rotary pusher that grips the casing reaches the limit as the weight of sediment adhering to the excavator blades increases. A failure is forced to occur.

  On the other hand, the enlargement of the earth and sand intake opening formed around the casing is naturally limited in terms of the strength of the casing itself. In some cases, it is also possible to move up and down intermittently with the casing, but this is the first method that can only be realized at the expense of excavation efficiency. It is not preferable.

  For this reason, there has been a request for development of an efficient method for capturing excavated sediment that enables the excavation process or work period to be shortened by smoothly incorporating the excavated sediment into the casing, leading to cost reduction.

  The present invention has been made paying attention to such problems, and at least on the premise of a construction method including a diameter expanding excavation process for finishing a shaft having a predetermined diameter so as to expand the preceding excavation hole. It is an object of the present invention to provide a diameter expansion excavation method and a diameter expansion excavation system in which earth and sand generated by diameter excavation can be easily taken into the bottom of a preceding excavation hole or a casing.

  The invention according to claim 1 includes a diameter expanding excavation process in which a hole drilled in the ground is expanded so as to expand the diameter of the hole, and in the diameter expanding excavation process, the diameter of the drilled hole is larger than that of the preceding excavation hole. The diameter of the preceding excavation hole is increased by a diameter expansion excavation means in which an expansion excavation blade is provided on the outer periphery of a small-diameter cylindrical steel pipe, and the sediment generated by the diameter expansion excavation is removed from the previous excavation hole and the steel pipe. It is characterized in that the soil is discharged from the steel pipe after being accumulated at the bottom of the preceding excavation hole through the gap.

  More specifically, as described in claim 2, it includes a preceding excavation step of excavating a prior excavation hole in the ground by the prior excavation means, and in this prior excavation step, the diameter is larger than the diameter of the steel pipe. In addition, a preceding excavation hole having a diameter smaller than the expanded excavation diameter is excavated.

  Therefore, in at least the invention described in claim 1, since a predetermined gap is always secured between the preceding excavation hole and the steel pipe at the time of the diameter expansion excavation, the earth and sand generated by the diameter expansion excavation is the same as the conventional one. Without staying at the base of the diameter-extended excavation blade, it falls through the gap and accumulates at the bottom of the preceding excavation hole. And since the sediment accumulated at the bottom of the preceding excavation hole can be grabbed by a soil removal means such as a hammer grab that moves up and down in the steel pipe, it is discharged to the outside of the steel pipe by this soil removal means. become.

  The invention according to claim 3 clarifies that the preceding excavation and the diameter expansion excavation are performed in parallel on the premise of the method according to claim 2. In combination, the prior excavation by the prior excavation means and the diameter expansion excavation by the diameter expansion excavation means are performed in parallel.

  More specifically, as described in claim 4, the preceding excavation is performed by an advanced excavating means provided in a position below the diameter-extended excavating blade in the steel pipe.

  Therefore, in the inventions according to claims 3 and 4, since both are performed simultaneously so that the preceding excavation precedes the diameter expansion excavation, the steel pipe that also functions as a part of the preceding excavation means The tip portion simultaneously becomes the bottom of the preceding excavation hole. Therefore, the earth and sand generated by the diameter expansion excavation are collected together with the earth and sand generated by the preceding excavation in the bottom part of the preceding excavation hole, that is, in the steel pipe, and then discharged to the outside by the earth discharging means.

  On the contrary, the invention described in claim 5 clarifies that the pre-excavation by the pre-excavation means and the diameter-expansion excavation by the large-diameter excavation means are independently performed on the premise of the method according to claim 2. According to the present invention, after the preceding excavation hole has been excavated by the preceding excavation means, the diameter-expanded excavation means is used instead of the preceding excavation means.

  In this case, as described in claim 6, when performing the diameter expansion excavation by the diameter expansion excavation means, the lower position of the diameter expansion excavation blade has an outer diameter substantially equal to or less than the preceding excavation hole. It is desirable to guide so that the diameter-extended drilling means is centered with respect to the preceding excavation hole by providing the guiding means and inscribing the guiding means to the preceding excavation hole.

  Therefore, in at least the invention described in claim 5, when the diameter expansion excavation is performed, a predetermined gap is already secured between the steel pipe of the diameter expansion excavation means and the preceding excavation hole. The earth and sand fall through the gap and collect at the bottom of the preceding excavation hole without staying at the root of the enlarged diameter excavation blade as in the prior art. And since the sediment accumulated at the bottom of the preceding excavation hole can be grabbed by a soil removal means such as a hammer grab that moves up and down in the steel pipe, it is discharged to the outside of the steel pipe by this soil removal means. become.

  Here, as described in claim 7, the preceding excavation is performed by the preceding excavation means in which the preceding excavation blade is provided on the outer periphery of the preceding excavation casing tube having substantially the same diameter as the steel pipe on the diameter expansion excavation means side. Shall.

  Further, in the preceding excavation, as described in claim 8, the sediment excavation opening formed on the front side in the excavation direction from the preceding excavation blade in the preceding excavation casing tube into the preceding excavation casing tube. The excavated soil will be taken in.

  In the preceding excavation, instead of the one described in claim 7, as described in claim 9, the diameter of the preceding excavation casing tube is substantially the same as the diameter of the preceding excavation hole. In addition to the above-described cylindrical second steel pipe, and can be performed by a prior excavation means in which a excavation blade is attached to the tip of the second steel pipe, It can also be carried out by preceding excavation means in which an excavation blade is attached to the tip of a cylindrical third steel pipe having a diameter larger than that of the steel pipe on the diameter expansion excavation means side and smaller than the diameter of the expanded excavation diameter.

  In some of the construction methods as described above, as described in claim 11, it is desirable to use a diameter-expanded excavating blade capable of expanding and contracting.

  In addition, according to claim 12, a spiral auxiliary wing is provided at a position below the enlarged diameter excavating blade in the steel pipe forming the enlarged diameter excavating means, and the earth and sand excavated by the enlarged diameter excavating blade It is desirable for efficient consolidation of excavated soil and sand to be pushed into the preceding excavation hole by the auxiliary wing along with the excavation rotation of the enlarged diameter excavating blade. As a result, it is possible to positively take in the earth and sand generated by the diameter expansion excavation into the bottom side of the preceding excavation hole and thus into the steel pipe.

  Of course, each of the above-described construction methods can be used for excavation inside the caisson or under the cutting edge of the caisson.

  Here, in constructing a shaft having a predetermined depth, excavation can be performed by the method according to claim 3 or 4 over the entire length of the shaft, and the depth of the shaft If the excavation has progressed to the middle of the depth, deeper excavation can be performed from the middle stage by the method according to claim 3 or 4, and the inventions according to claims 14 and 15 clearly indicate these facts. It has become.

  Similarly, in the construction of a shaft with a predetermined depth, excavation can be performed by the method according to claim 5 over the entire length of the shaft, and the depth of the shaft can be determined. If excavation has progressed to the middle, deeper excavation can be carried out from the middle stage by the method according to claim 5, and the inventions according to claims 16 and 17 clarify these things.

  The invention described in claim 18 captures the technique described in claim 3 or 4 as a diameter-expanded excavation system, and has a diameter-excavated blade on the outer periphery of a cylindrical steel pipe having a diameter smaller than that of the preceding excavation hole. An expanded diameter drilling means provided, and a preceding one that is provided at a position lower than the expanded diameter drilling blade of the steel pipe and capable of drilling a preceding drilled hole having a diameter larger than the steel pipe and smaller than the expanded diameter drilling diameter. Excavation means, rotary push-in means for pushing the steel pipe into the ground while rotating the steel pipe together with the enlarged diameter excavation blade and the preceding excavation means, and moving up and down in the steel pipe to grasp the earth and sand in the steel pipe Furthermore, it is characterized by having a soil removal means for soiling outside the steel pipe.

  The invention described in claim 19 captures the technique described in claim 5 or 6 as a diameter-expanded drilling system, and has a diameter-excavated blade on the outer periphery of a cylindrical steel pipe having a diameter smaller than that of the preceding drilled hole. Expanded drilling means provided, preceding drilling means capable of drilling a preceding drilling hole having a diameter larger than that of the steel pipe and smaller than the expanded drilling diameter, and holding the steel pipe and expanding the steel pipe Rotating and pushing means for pushing into the ground while rotating together with the excavating blades, and earth removing means for moving up and down in the steel pipe to grab the earth and sand in the steel pipe and discharging it outside the steel pipe To do.

  Furthermore, the invention described in claim 20 captures the technique described in claim 6 as a diameter-expanded excavation system, and has a diameter-excavated blade on the outer periphery of a cylindrical steel pipe having a diameter smaller than that of the preceding excavation hole. Expanded drilling means provided, preceding drilling means capable of drilling a preceding drilling hole having a diameter larger than that of the steel pipe and smaller than the expanded drilling diameter, and holding the steel pipe and expanding the steel pipe Rotating push-in means for pushing into the ground while rotating together with the excavating blade, and provided at a position lower than the enlarged-diameter excavating blade in the steel pipe and having an outer diameter substantially equal to or less than that of the preceding excavation hole, Inducting means for guiding the diameter-expanded drilling means to be centered with respect to the preceding drilling hole by inscribed in the preceding drilling hole at the time of excavation, and moving up and down in the steel pipe to grasp the earth and sand in the steel pipe Equipped with soil removal means for soil removal outside the steel pipe Characterized in that was.

  According to the first and second aspects of the present invention, at least when the diameter expansion excavation means performs the diameter expansion excavation means, a predetermined gap is always ensured between the steel pipe of the diameter expansion excavation means and the preceding excavation hole. Therefore, the earth and sand generated by the diameter expansion excavation does not stay at the base of the diameter expansion excavation blade as in the conventional case, and is surely taken into the bottom of the preceding excavation hole and then into the steel pipe. As a result, the earth and sand intake efficiency is greatly improved.

  In particular, according to the invention described in claims 3 and 4, since the preceding excavation and the diameter expansion excavation are performed in parallel, workability is improved in addition to the same effects as the invention described in claim 1, The excavation process or construction period can be greatly shortened.

  According to the invention described in claim 5, the preceding excavation and the diameter expansion excavation are performed independently of each other, and the diameter expansion excavation is always performed between the steel pipe of the diameter expansion excavation means and the preceding excavation hole. Since the predetermined gap is secured, the earth and sand generated in the diameter expansion excavation is surely collected at the bottom of the preceding excavation hole through the gap and then discharged by the earth removing means that moves up and down in the steel pipe. Therefore, as in the case of the first aspect of the invention, the earth and sand intake efficiency is greatly improved.

  According to the sixth aspect of the present invention, the presence of the guiding means guides the enlarged drilling means so that the enlarged drilling means is centered with respect to the preceding drilling hole. The concentric accuracy with the diameter excavation hole is improved, and more efficient excavation can be performed during the diameter expansion excavation.

  According to the eighth aspect of the present invention, since the excavated sediment can be actively taken into the preceding excavation casing tube from the sediment intake port formed in the preceding excavation casing tube, the sediment intake efficiency is further improved. To do.

  According to the twelfth aspect of the present invention, the effect of pushing the sediment generated in the diameter-expanded excavation to the preceding excavation hole side can be expected by the function of the spiral auxiliary wing. Capture efficiency is dramatically improved.

  According to the invention described in claim 13, since the excavation is performed inside the caisson or under the edge of the caisson by the above-described methods, the caisson press-fitting and setting work can be efficiently performed along with the improvement of the sediment intake efficiency. .

  FIG. 1 is an explanatory view showing the basic concept of a first embodiment of a diameter expansion excavation method and a diameter expansion excavation system according to the present invention. This embodiment corresponds to the inventions described in claims 10, 11 and 16, 19 in addition to the inventions described in claims 1, 2 and 5, respectively.

  In the first embodiment, when constructing a shaft H2 having a predetermined depth with a diameter D3 shown in FIG. 1B, as shown in FIG. 1A, a preceding excavation hole H1 with a diameter D2 is advanced. The construction is divided into the preceding excavation process and the enlarged excavation process in which the preceding excavation hole H1 is expanded to the diameter D3 and finished to the same diameter shaft H2 as shown in FIG. .

  In the preceding excavation step of FIG. 1A, a pipe-shaped preceding excavation casing tube 1 as an advance excavating means having a diameter equivalent to the diameter D2 of the preceding excavation hole H1 to be excavated, and the preceding excavation casing tube 1 The rotary push-in device 2 that functions as a driving device for the machine and the hammer grab 3 as the earthing means are used in combination, and a plurality of excavating blades 4 are implanted at the tip of the preceding excavation casing tube 1. It is. The rotary push-in device 2 has a function equivalent to that of the drive unit of the all-swivel all-casing excavator, and has the function of rotating and driving the preceding excavation casing tube 1 after chucking (gripping) it. In parallel with the rotational drive of the digging casing tube 1, the digging casing tube 1 has a function of applying thrust to the preceding excavation casing tube 1 and press-fitting it into the ground. The preceding excavation casing tube 1 corresponds to a “cylindrical third steel pipe” according to claim 9 or the like.

  Therefore, in the preceding excavation step of FIG. 1A, as described above, the preceding excavation casing tube 1 chucked by the chuck portion of the rotary push-in device 2 is pressed into the ground while being rotationally driven, and in parallel therewith. Then, the hammer grab 3 is moved up and down in the preceding excavation casing tube 1 so as to correspond to the bottom of the preceding excavation hole H1 being excavated, that is, the tip of the preceding excavation casing tube 1. The earth and sand cut out by the portion is excavated by the hammer grab 3 and is then taken out of the preceding excavation casing tube 1.

  As the excavation depth increases, the casing piece 1a, which is a unit element constituting the preceding excavation casing tube 1, is constructed while being sequentially added to the upper end of the existing excavation casing tube 1. To do. When the predetermined depth is reached, the preceding excavation casing tube 1 is pulled up to form the preceding excavation hole H1 having the same diameter as the diameter D2 of the preceding excavation casing tube 1.

  In the diameter expansion excavation process of FIG. 1B following the preceding excavation, the diameter expansion excavator 5 as the diameter expansion excavation means, the rotary push-in apparatus 2A similar to that shown in FIG. It is assumed that construction is performed using a hammer grab 6 which is a soil means.

  As shown in FIG. 2 in addition to FIG. 2B, the enlarged diameter excavator 5 includes, for example, three sets of pipes around a casing 7 having a smaller diameter than the preceding excavation casing tube 1 in FIG. The substantially blade-shaped expanded drilling blades 8 are mounted at an equal pitch, and the diameter of the locus drawn by the maximum diameter portion at the tip of these expanded drilling blades 8 is the diameter D3 of the shaft H2 to be constructed earlier. Is set to the same size. Thereby, the correlation between the diameter D1 of the casing 7, the diameter D2 of the preceding excavation hole H1, and the diameter D3 of the shaft H2 is set in advance such that D1 <D2 <D3. The casing 7 corresponds to the “cylindrical steel pipe” described in claim 1 and the like.

  Further, in the casing 7, a position that is at the same height as the lower base portion of the enlarged diameter excavating blade 8 and that does not interfere with the enlarged diameter excavating blade 8 is simplified so as to communicate the inside and outside of the casing 7. A rectangular earth-and-sand intake port 9 is formed as an opening, and the lower surface of the enlarged-diameter excavation blade 8 and the tip of the general portion of the casing 7 left below the enlarged-diameter excavation blade 8 are for leading excavation. A plurality of excavating blades 4 are implanted in the same manner as the casing tube 1. The lower surface of each of the enlarged diameter excavating blades 8 is formed in a taper shape, and therefore, the locus drawn by the lower surface of the enlarged diameter excavating blade 8 by its rotation is set to be substantially conical.

  Each of the above-mentioned enlarged diameter excavation blades 8 is formed by a fixed blade 8a and a movable blade 8b arranged so as to overlap therewith as shown in FIG. The diameter can be expanded and contracted by sliding displacement along the fixed wing 8a. The details of this structure will be described later.

  Therefore, in the diameter expanding excavation step shown in FIG. 1B, the tip end portion of the casing 7 gripped by the rotary push-in device 2A is concentrically inserted into the preceding excavation hole H1, while being attached to the casing 7. The diameter-extended excavation blade 8 is in an expanded state, and is pressed into the ground while being rotationally driven together with the casing 7, and excavated so as to expand the preceding excavation hole H1, and finished to a shaft H2 having a predetermined diameter D3. It will be. In parallel with this, the hammer grab 6 is moved up and down in the casing 7, and the sand and sand accumulated at the position corresponding to the bottom of the preceding excavation hole H <b> 1 that is to be expanded in diameter from the top is excavated with the hammer grab 6. Grabbing it while holding it out removes it from the casing 7.

  In the process of this diameter expansion excavation, since the diameter D2 of the preceding excavation hole H1 and the diameter D1 of the casing 7 have a relationship of D1 <D2, there is D1 between the casing 7 and the inner peripheral surface of the preceding excavation hole H1. A gap A corresponding to the difference between D2 and D2 is always secured. Therefore, the earth and sand excavated by the enlarged diameter excavating blade 8 are gathered near the casing 7 with the rotation of the enlarged diameter excavating blade 8, that is, near the root portion of the enlarged diameter excavating blade 8 with respect to the casing 7. A will be collected at the bottom of the preceding excavation hole H1 through A. At the same time, part of the earth and sand is taken into the casing 7 from the earth and sand taking-in opening 9 formed in the casing 7 and then falls to the bottom of the preceding excavation hole H1.

  Therefore, the earth and sand generated by the diameter expansion excavation may stay in the vicinity of the root portion of the diameter expansion excavation blade 8 as in the prior art, or may stay in the compacted state due to the retention and adhere to the entire diameter expansion excavation blade 8. The excavation earth and sand taking-in efficiency to the bottom side of the preceding excavation hole H1 is very good. Then, the earth and sand collected at the bottom of the preceding excavation hole H1 is discharged by the hammer grab 6 that moves up and down in the casing 7 as described above.

  Here, based on the difference between the diameter of the preceding excavation casing tube 1, that is, the diameter D2 of the preceding excavation hole H1 and the diameter D1 of the casing 7, a gap A is positively secured between them, and the gap A is used. Therefore, it is desirable that the diameter D2 of the preceding excavation hole H1 is at least 1.1 times the diameter D1 of the casing 7 because the falling of the earth and sand generated during the diameter expansion excavation and the efficiency of the intake thereof are to be improved.

  3 and 4 are diagrams showing a second embodiment of the present invention, and the same reference numerals are given to the parts common to the first embodiment. This embodiment corresponds to the inventions described in claims 7, 8, and 11, 14, 18 in addition to the inventions described in claims 1-4.

  In the second embodiment, the preceding excavation for the purpose of excavating the preceding excavation hole H1 having the diameter D2 and the diameter-expanding excavation for expanding the preceding excavation hole H1 to finish the shaft H2 having the predetermined diameter D3. A part of the diameter-expanding excavator 5 which is a diameter-expanding excavating means substantially serves as a preceding excavating means as will be described later.

  As shown in FIG. 3, a casing attachment 10 for a leading excavating blade having substantially the same diameter, which forms a part of the casing 7, is attached to and detached from the tip of the casing 7 having a diameter D <b> 1 that is a main element of the diameter expanding excavation means. For example, three preceding excavation blades 11 are attached to the outer periphery of the casing attachment 10 as shown in FIG.

  As shown in an enlarged view in FIG. 5, the preceding excavation blade 11 has a plurality of excavation blades 13 planted at the lower end of a blade 12 bent in a substantially U shape in plan view, and the back side is a reinforcing plate. 14, and at the same time, the cylindrical body portion of the casing attachment 10 is close to each preceding excavation blade 11, that is, at the same height as the preceding excavation blade 11 and the preceding excavation blade 11. Further, a rectangular soil intake port 15 is formed at the front side in the excavation direction. And the diameter of the locus which the tip (maximum diameter part) of each preceding excavation blade 11 draws is set to the same size as diameter D2 of preceding excavation hole H1 which should be excavated. In addition, a plurality of excavating blades 4 are implanted at the lower end of the casing attachment 10 in the same manner as shown in FIG. 1. Therefore, the casing attachment 10 is a part of the casing 7 but also with the preceding excavating blade 11. Forms a pre-drilling means.

  Therefore, according to the second embodiment, the casing 7 gripped by the rotary push-in device 2A is press-fitted into the ground while being rotationally driven, whereby the leading excavation hole H1 having the diameter D2 by the leading excavation blade 11 is advanced. And the diameter expansion excavation which finishes the preceding excavation hole H1 with the diameter expansion excavation blade 8 and finishes it into the shaft H2 of the diameter D3 is performed simultaneously.

  In this case, the positional relationship in the vertical direction between the preceding excavating blade 11 and the diameter-expanded excavating blade 8 that rotate at the same time is always unchanged, so that the preceding excavating hole H1 just excavated by the preceding excavating blade 11 is chased from above. Thus, the diameter-expanded excavation blade 8 performs diameter-expanded excavation.

  Since the preceding excavation hole H1 having a predetermined depth is always ensured below the enlarged diameter excavation blade 8, a part of the earth and sand generated by the excavation of the enlarged diameter excavation hole H2 is on the casing 7 side. While being taken into the casing 7 from the earth and sand intake port 9 and collected in the deepest part of the preceding excavation hole H1 (the part where the tip of the casing attachment 10 is located), much of the earth and sand generated by the diameter expansion excavation immediately precedes it. It falls down through the gap A between the excavation hole H1 and the casing 7 and accumulates at the bottom of the preceding excavation hole H1 where the preceding excavation blade 11 is located. The sediment accumulated at the level position of the preceding excavation blade 11 is transferred to the interior of the casing attachment 10 from the sediment intake port 15 of the casing attachment 10 together with the sediment excavated by the prior excavation blade 11 itself, that is, the preceding excavation hole H1 as described above. Are collected in the deepest part (the part where the tip of the casing attachment 10 is located).

  Thereafter, the earth and sand thus taken into the casing attachment 10 is discharged by the hammer grab 6 that moves up and down in the casing 7 as in the previous embodiment.

  FIG. 6 shows a third embodiment of the present invention. In this embodiment, the structure of the preceding excavation blade 11 shown in FIGS. 3 and 5 is the same as that shown in FIG. This is applied to the casing tube 16 for excavation. This embodiment corresponds to the inventions described in claims 7, 8 and 11, 16, 19 in addition to the inventions described in claims 1, 2 and 5, respectively.

  As shown in FIG. 6 (A) and FIG. 7, the preceding excavation blade casing attachment 10 having the diameter D1 shown in FIG. 5 is connected to the lower end of the preceding excavation casing tube 16 having the diameter D1, and the casing attachment 10 is connected to the casing attachment 10. A plurality of preceding excavation blades 11 that draw a tip locus of diameter D2 (D2> D1) are mounted. Further, as shown in FIG. 5, the casing attachment 10 is formed with an earth and sand intake port 15 adjacent to the preceding excavation blade 11.

  Therefore, according to the third embodiment, as shown in FIG. 6A, when the casing attachment 10 is driven into the ground while being rotationally driven by the rotary push-in device 2A together with the preceding excavation casing tube 16, Even if the diameter of the preceding excavation casing tube 16 is D1, since the diameter of the locus drawn by the tip of the preceding excavation blade 11 attached to the casing attachment 10 is D2, as a result, the preceding excavation hole H1 having the diameter D2 is excavated. Will be. The earth and sand generated by the preceding excavation are taken into the casing attachment 10 from the earth and sand intake port 15 and discharged by the hammer grab 6 that moves up and down in the preceding excavation casing tube 16.

  6 (B) following the preceding excavation is exactly the same as that shown in FIG. 1 (B), and the diameter of the preceding excavation hole H1 having the diameter D2 is expanded by the enlarged excavation blade 8. In this way, the enlarged diameter excavation hole having the diameter D3, that is, the shaft H2 is finished.

  In this case, as in the first embodiment shown in FIG. 1, the diameter of the casing 7 on which the diameter-extended excavation blade 8 is mounted is D1, whereas the diameter of the preceding excavation hole H1 is D2. Since a gap A of the difference between the diameters D2 and D1 is secured between the two, the earth and sand generated by the diameter expansion excavation by the diameter expansion excavation blade 8 smoothly falls through the gap A, and the preceding excavation It will be collected at the bottom of the hole H1. A part of the earth and sand passes through the inside of the casing 7 from the earth and sand intake port 9 of the casing 7 and is collected at the bottom of the preceding excavation hole H1 in the same manner as described above.

  Therefore, also in the third embodiment, the earth and sand generated by the diameter expansion excavation stays near the root portion of the diameter expansion excavation blade 8 as in the prior art, or becomes a compacted state again due to the retention and expands. It will not adhere to the entire diameter excavation blade 8, and the efficiency of taking excavated soil into the bottom side of the preceding excavation hole H1 will be extremely good. Then, the earth and sand collected at the bottom of the preceding excavation hole H1 is discharged by the hammer grab 6 that moves up and down in the casing 7 as described above.

  8 to 15 show the details of the main part of the above-mentioned enlarged diameter excavation blade 8 shown in FIGS. 3 and 6, and as shown in FIGS. 8 and 9, the tip of the casing 7 formed by connecting a plurality of casing attachments. In this section, a casing attachment 17 for an enlarged excavation blade and a casing attachment 10 for a preceding excavation blade having the same diameter as that of the casing 7 are sequentially connected in series from the upper stage so as to be detachable in series with bolts and nuts not shown. Each of these casing attachments 10 and 17 also forms part of the casing 7. Further, as will be described later, a plurality of diameter-enlarged excavation blades 8 each having a fixed wing 8a and a movable wing 8b, which can be expanded and contracted, are mounted on the casing attachment 17 for the diameter-extended excavation blades. In addition, the casing attachment 10 for leading excavation blades has the some leading excavation blade 11 as shown in FIG.

  As shown in FIG. 10, a flat box-shaped bracket 19 having a seating surface 19a for the enlarged-diameter excavating blade 8 described later is fixed to the casing attachment 17 for the enlarged-excavating blade as shown in FIG. It is. The bracket 19 is set so that the seating surface 19a is parallel to the tangential direction of the casing attachment 17 for the enlarged diameter excavating blade, and a number of mounting holes 20 are regularly formed in the seating surface 19a.

  On the other hand, as shown in FIGS. 11 and 12, the diameter-excavated excavation blade 8 is formed by slidably overlapping a flat plate-shaped fixed blade 8a and a flat plate-shaped movable blade 8b smaller than the fixed blade 8a. A large number of mounting holes 22 are regularly formed in the blade 8a in the same manner as the bracket 19 on the casing attachment 17 side for the enlarged diameter excavating blade described above. As is clear from the figure, the fixed wing 8a is seated on the seating surface 19a of the bracket 19, and the mounting holes 20, 22 on the bracket 19 side and the fixed wing 8a side are matched with each other, The diameter-extended excavation blade 8 is detachably fixed to the bracket 19 with a nut 29. That is, the diameter-extended excavation blade 8 is detachably fixed to the bracket 19 so as to largely protrude in a tangential direction of the casing 7 or a direction parallel thereto in a plan view.

  Here, not all of the numerous mounting holes 20 and 22 formed in the bracket 19 and the fixed blade 8a as described above are used at the same time. 11 and 12, the distance a from the center of the enlarged-diameter excavating blade casing attachment 17 to the tip of the movable vane 8b, that is, the rotational radius of the enlarged-excavated vane 8 is appropriately changed. It can be adjusted in stages.

  As shown in FIGS. 13 and 14 in addition to FIGS. 11 and 12, the enlarged diameter excavating blade 8 has the movable blade 8b superimposed on the surface of the fixed blade 8a on the rotational direction side when the rotational direction is the clockwise direction. The movable blade 8b is slidably guided and supported by a blade guide 23 provided on the fixed blade 8a so as to move along the fixed blade 8a. In addition, an expansion / contraction diameter cylinder (hydraulic cylinder) 25 is mounted as a direct acting actuator on the back side of the fixed wing 8a toward the rotation direction, that is, the surface opposite to the rotation direction of the fixed wing 8a. is there. The piston rod 26 of the expansion / contraction diameter cylinder 25 is connected to one end of a slider 27 located on the opposite side of the fixed wing 8a, and the other end of the slider 27 is opposite to the fixed wing 8a. As a result, the expansion / contraction diameter cylinder 25 is disposed in a bridging manner so as to straddle the fixed wing 8a and the movable wing 8b. Therefore, by operating the expansion / contraction diameter cylinder 25 to expand and contract, the movable blade 8b slides relative to the fixed blade 8a by the stroke of the expansion / contraction diameter cylinder 25, and as a result, expands in the tangential direction of the casing 7 or in a direction parallel thereto. The diameter excavation blade 8 has a structure capable of expanding and contracting.

  A plurality of excavating blades (bits) 4 are attached to the lower ends of the fixed wing 8a and the movable wing 8b forming the diameter-extended excavating wing 8.

  Here, the expansion / contraction diameter cylinder 25 is mounted on the surface on the counter-rotation direction side of the fixed wing 8a because the expansion / contraction diameter cylinder 25 is moved from the earth, sand, rock, or the like to which the diameter expansion wing 8 is directed during excavation. This is to protect 25. 12 and 15, the expansion / contraction diameter cylinder 25 is set so that the expansion direction of the expansion / contraction diameter cylinder 25 is opposite to the diameter expansion / sliding direction of the movable blade 8b. The diameter-expanded excavating blade 8 is set in the expanded state in the contracted state, and conversely, the diameter-extended excavating blade 8 is set in the contracted state in the expanded state of the expansion / contraction diameter cylinder 25.

  Further, as shown in FIGS. 11 and 13, between the adjacent brackets 19 and 19 of the casing attachment 17 for a large-diameter excavating blade, a substantially rectangular earth and sand intake port 9 is formed as an opening. As a result, regardless of whether the expanded diameter excavating blade 8 is in the expanded state or the reduced diameter state, a part of the earth and sand excavated by the expanded diameter excavating blade 8 passes through the sediment intake port 9 and the casing 7 (expanded diameter excavation). It can be taken into the wing casing attachment 17).

  Regardless of whether the expanded diameter excavating blade 8 is in an expanded state or a reduced diameter state, the hydraulic pressure supply path of the expanded / reduced diameter cylinder cylinder 25 is hydraulically locked to increase or decrease the diameter. The state will be self-maintained.

  FIGS. 16 to 20 show a fourth embodiment of the present invention. In this fourth embodiment, the caisson 30 is press-fitted and provided with a rotary push-in device 2A similar to FIG. The example in the case of excavating under the so-called cutting edge (blade edge) of the caisson 30 with the excavator 5 is shown. This embodiment corresponds to the inventions described in claims 11, 13 and 14, 18 in addition to the inventions described in claims 1-4.

  While the caisson 30 is press-fitted and submerged, the press-fitting and excavation are repeated while excavating the earth and sand inside the existing caisson 30 that has been pre-fitted as is well known. The press-in set-up is performed while adding 30a.

Here, for example, it is assumed that a shaft with an inner diameter of 5.0 m and an outer diameter of 6.0 m is built up to about 40 m underground in the hard ground. It is assumed that the ground is composed of hard ground such as mudstone having a strength of about 5000 to 7000 kN / m ^{2 at a} depth of about 30 m or more.

  Further, the diameter of the casing 7 in the diameter-excavated excavator 5 is 2 m, the diameter of the excavated diameter by the fixed wing 8 a when the diameter-extended digging blade 8 is most contracted is 4.5 m, and the diameter-extended digging blade 8 is expanded most. The excavation diameter at that time is 6 m, and the excavation diameter by the preceding excavation blade 11 is 3 m.

  FIG. 17 and subsequent drawings show a construction procedure by the diameter expanding excavator 5 shown in FIG. 16, and the depth of the caisson 30 cutting edge reaching the hard ground (around 30 m underground in the above example) is shown in FIG. 17. As shown in (A) to (B), the assembly and construction of the caisson 30, the press-fitting and sinking by the press-fitting and sinking device 31 such as a hydraulic jack, and the excavation by the bucket system excavating means 32 such as a clamshell are repeated.

  When the caisson 30 is press-fitted and settled until it reaches the hard ground, a temporary cradle 33 is installed to prevent the caisson 30 from self-sinking as shown in FIG. Further, as shown in FIG. 4D, the diameter-extended excavator 5 provided with the preceding excavation blade 11 in addition to the rotary push-in device 2 described above is set on the upper part of the caisson 30. At this time, it is assumed that the diameter-excavated wing 8 composed of the fixed wing 8a and the movable wing 8b is in a reduced diameter state, and the diameter of the diameter-extended digging wing 8 is set to 4.5 m. .

  Then, as shown in FIGS. 18A and 18B, as the primary excavation, the preceding excavation by the preceding excavation blade 11 and the excavation in the reduced diameter state of the diameter-expanded excavation blade 8 are performed simultaneously in parallel. When the excavating blade 8 reaches the portion below the cutting edge of the caisson 30, the diameter-expanding excavating blade 8 is expanded as shown in FIG. The diameter is assumed to be set to 6 m), and deeper excavation, that is, excavation at a depth of about 40 m as shown in FIG. At this time, after the preceding excavating blade H1 having a diameter of 3 m has been excavated by the preceding excavating blade 11, the drilling is performed so that the diameter of the preceding excavating hole H1 is increased to 4.5 m or 6 m. In addition, the tip of the leading excavation hole H1 always has a stepped shape due to the difference in diameter between the casing attachment 10 to which the leading excavation blade 11 is attached and the leading excavation blade 11. Moreover, in the transient state until the diameter-expanded excavation blade 8 changes from the reduced diameter state to the complete diameter-expanded state, the excavation diameter by the diameter-extended excavation blade 8 gradually increases and changes.

  In addition, in the process of primary excavation up to the state shown in FIG. 18D, the hammer grab 6 moves up and down in the casing 7 in parallel, and the accumulated sediment at the bottom of the preceding excavation hole H1, That is, the earth and sand accumulated in the casing attachment 10 is discharged. In this case, as shown in FIG. 16, part of the earth and sand excavated by the enlarged diameter excavating blade 8 is taken into the casing 7 from the earth and sand intake port 9 formed in the casing 7, and a lot of earth and sand is preceded. The dead weight falls to the height of the preceding excavation blade 11 through the gap between the excavation hole H1 and the casing 7 and is collected near the bottom of the preceding excavation hole H1 and is put on the casing attachment 10 together with the earth and sand excavated by the preceding excavation blade 11. It will be taken in into the casing attachment 10 from the earth-and-sand taking-in opening 15 formed with opening.

  When excavation and soil removal to a predetermined depth are completed as shown in FIG. 18D, after removing the rotary push-in device 2 and the diameter expansion excavator 5 as shown in FIG. The high quality soil G is introduced from the upper part of the caisson 30 and back filling is performed up to the lower part of the caisson 30 in the enlarged diameter drilling hole H3 excavated earlier.

  When the backfilling is completed in this manner, the connection between the caisson temporary support base 33 and the caisson 30 is released, and the caisson temporary support base 33 is removed. At this time, the caisson provisional cradle 33 and the caisson 30 are disconnected while confirming that the caisson 30 does not self-sink. Do more.

  After that, as shown in FIGS. 19B to 19D, the caisson 30 is constructed (addition of segments), the caisson 30 is press-fitted and the inside of the caisson 30 is excavated by the clamshell 32, and a predetermined depth is obtained. It is assumed that the caisson 30 is press-fitted and installed.

  When the caisson 30 is press-fitted and submerged to a predetermined depth in this way, as shown in FIGS. 20 (A) and 20 (B), after the slime deposited on the bottom plate portion of the enlarged diameter drilling hole H3 is processed, the bottom concrete C is placed. . Thus, a predetermined shaft is constructed with the caisson 30.

  Here, in the above embodiment, the diameter of the enlarged diameter drilling hole H3 is 6.0 m, which is the same as the outer diameter of the caisson 30, but the diameter of the expanded diameter drilling hole H3 is equal to or larger than the inner diameter (5.0 m) of the caisson 30. If the unexcavated portion that can withstand the weight of the caisson 30 is left under the cutting edge of the caisson 30 by setting it to less than 6.0 m, the high-quality soil G as shown in FIG. The backfilling work by is no longer necessary and can be abolished.

  That is, although FIGS. 21A to 21D show the same state as FIGS. 18A to 18D, the diameter of the expanded drilling hole H3 is, for example, the inner diameter of the caisson 30 (5.0 m). ) And different from FIG. 18 in that the outer diameter of the caisson 30 is set to be less than 6.0 m.

  Then, as shown in FIG. 22 (A), if the diameter-expanded excavation hole H3 having a predetermined depth is formed, then backfilling with high-quality soil is performed as shown in FIGS. (B) and (C). When the caisson 30 is pressed and submerged without increasing the depth of the caisson 30, the depth of the drilling hole H3 is appropriately increased by the clam shell 32 or the like as shown in FIGS. It is assumed that the earth and sand M accumulated at the bottom is excavated and discharged.

  FIGS. 23A and 23B are in the same state as FIGS. 20A and 20B. As shown in FIGS. 23A and 23B, the bottom plate portion of the enlarged diameter drilling hole H3 is formed. After processing the accumulated slime, the bottom base concrete C is placed. Thus, a predetermined shaft is constructed with the caisson 30.

  Here, FIGS. 21 to 23 show an example of the case where the caisson 30 is press-fitted exclusively after the diameter-expanded excavation hole H3 having a predetermined depth is formed in the hard ground, but FIG. 25 described later also in the hard ground. In addition to ˜27, as in FIGS. 35 to 37 and FIGS. 38 to 40, the caisson 30 is press-fitted each time the digging of the enlarged digging hole H3 is advanced by a predetermined amount. Of course, it is possible to adopt a construction method in which 30 press-fittings are alternately repeated.

  FIG. 24 shows a fifth embodiment of the present invention, and the same reference numerals are given to the parts common to the parts shown in FIG. 3 as the second embodiment. This embodiment corresponds to the inventions described in claims 11 and 12 and claims 14 and 18 in addition to the inventions described in claims 1 to 4, respectively.

  In the fifth embodiment, as shown in FIG. 24, it is a part of the casing 7 to which the enlarged diameter excavating blade 8 is mounted, and corresponds to between the enlarged diameter excavating blade 8 and the preceding excavated blade 11. A single and spiral auxiliary wing 40 having a predetermined twist angle is mounted at a position to be mounted. Then, assuming that the casing 7 is driven to rotate in the clockwise direction similar to the tightening direction of the right screw, for example, the auxiliary wing 40 has a twist angle equivalent to that of the left screw and its diameter Is set smaller than the diameter D2 of the preceding excavation hole H1. The auxiliary wing 40 rotates in the same direction when both the leading excavation blade 11 and the enlarged diameter excavation blade 8 mounted on the common casing 7 are excavated and rotated in the clockwise direction, and at least the leading excavation blade 11 is rotated. It has a function to push the earth and sand generated in the preceding excavation by the lower side than the auxiliary wing 40.

  According to the fifth embodiment, when the pre-excavation by the pre-excavation blade 11 and the diameter expansion excavation by the large-diameter excavation blade 8 are performed in parallel, the auxiliary wing 40 has the earth and sand above it as the auxiliary While allowing the earth and sand to fall below the wing 40, the earth and sand below the auxiliary wing 40 is pushed downward by the auxiliary wing 40. As a result, positive soil uptake from the soil uptake opening 15 formed in the opening 10 to the inside is promoted, and the soil uptake efficiency is further improved.

  FIGS. 25 to 27 show a sixth embodiment of the present invention. In this sixth embodiment, the causson 30 is press-fitted and provided with a rotary pushing device 2A similar to FIG. An example in which the excavator 5 excavates the inside of the caisson 30 and below the so-called cutting edge (blade edge) of the caisson 30 is shown. This embodiment corresponds to the inventions described in claims 11, 13 and 14, 18 in addition to the inventions described in claims 1-4.

  In this embodiment, in addition to excavation of the inside of the caisson 30 prior to press-fitting the caisson 30, all excavation up to excavation under the cutting edge of the caisson 30 that has been press-fitted, that is, all necessary for press-fitting the caisson 30 is performed. Excavation is performed by the rotary pusher 2A shown in FIG. 24 and the diameter expanding excavator 5 having the preceding excavating blade 11. The press fitting of the caisson 30 is performed as described above with respect to the existing caisson 30 that has been preceded by press fitting. While the press-fitting and excavation are repeated while excavating the earth and sand, press-fitting and sinking is performed while adding a so-called circular segment 30a on the existing caisson 30.

  As shown in (A) of FIG. 25, if the rotary push-in device 2A, the enlarged diameter excavator 5 and the like are set on the ground in addition to the press-fitting and sinking device 31 such as the caisson 30 and the hydraulic jack, the same figure (B) is obtained. As shown, the casing 7 is pushed into the ground while being rotationally driven, and the caisson 30 is excavated by using the preceding excavating blade 11 and the enlarged diameter excavating blade 8 together. At this stage, the enlarged diameter excavating blade 8 is in a reduced diameter state.

  When the diameter-extended excavation blade 8 reaches below the cutting edge of the caisson 30, the diameter-expanded excavation blade 8 is expanded as shown in the same figure (C) and then advanced excavation as shown in the same figure (D). The excavation by the blade 11 and the enlarged diameter excavation blade 8 and the press-fitting of the caisson 30 by the press-fitting and setting device 31 are repeated. When the first-stage caisson 30 (segment 30a) is press-fitted to a predetermined depth, the caisson 30 (segment 30a) is added as shown in FIG. 26A, and as shown in FIG. Excavation by the leading excavation blade 11 and the diameter expansion excavation blade 8, press-fitting of the caisson 30 by the press-fitting and sinking device 31 as shown in FIG. 10C, and addition with the caisson 30 (segment 30a) as shown in FIG. In addition to the above, further excavation by the leading excavation blade 11 and the diameter-expanding excavation blade 8 as shown in FIG. 27A and press-fitting of the caisson 30 by the press-fitting and sinking device 31 as shown in FIG. It becomes possible to press-fit the caisson 30.

  After the caisson 30 has been press-fitted and settled, the diameter-extended excavating blade 8 is reduced, and the diameter-excavating machine 5 including the preceding excavating blade 11 is pulled out together with the casing 7 to the ground. As a result, a shaft with a predetermined depth is constructed with the caisson 30. Needless to say, the bottom base concrete C is placed as necessary as in FIG.

  28 to 30 show another example of the diameter expanding excavation process as the seventh embodiment of the present invention. In the third embodiment, the part common to the part shown in FIG. Are given the same reference numerals. This embodiment corresponds to the inventions described in claims 9, 11, 12 and claims 16, 19, 20 in addition to the inventions described in claims 1, 2, 5 and 6, respectively.

  In the seventh embodiment, as shown in FIG. 29 in addition to FIG. 28, a part of the casing 7 that forms the diameter expansion excavation means together with the diameter expansion excavation blade 8, that is, a part of the casing 7. A stabilizer 50 as a guiding means is provided at a position lower than the diameter-extended excavation blade 8 in a casing attachment 17 for an enlarged diameter excavation blade.

  29 and 30, the stabilizer 50 has a ring-shaped guide ring 51 disposed concentrically on the outer periphery of the casing attachment 17 for a large-diameter excavating blade via three radial support arms 52. As shown in FIG. The outer diameter of the guide ring 51 is set to be the same diameter as the preceding excavation hole H1 or slightly smaller than that.

  Therefore, according to the seventh embodiment, when performing diameter expansion excavation with the diameter expansion excavation blade 8 as shown in FIG. 28, the stabilizer positioned below the diameter expansion excavation blade 8. Since 50 guide rings 51 are inscribed in the preceding excavation hole H1, a so-called anti-vibration effect of the diameter-expanded excavation blade 8 is exhibited, and centering of the diameter-expanded excavation blade 8 with respect to the preceding excavation hole H1 is achieved. As is done, the enlarged diameter excavation blade 8 is autonomously guided. Therefore, the concentric accuracy of the preceding excavation hole H1 and the enlarged diameter excavation hole H2 to be formed by expanding the diameter is improved, and the diameter expansion is obvious as compared with FIG. 6B. In the casing attachment 17 for excavation blades, there is an advantage that the protruding length downward from the diameter-excavated excavation blade 8 can be reduced.

  In the seventh embodiment, when the hammer grab 6A as the earth removing means is moved up and down, it is considered not to interfere with the lower end portion of the casing attachment 17 for the enlarged diameter excavation blade. As shown, it is desirable to use a hammer grab 6A having a smooth outer shape, and to form a skirt portion 17a having a tapered shape or a diverging shape at the lower end of the casing attachment 17 for the enlarged diameter excavating blade.

  31 to 34 show an eighth embodiment of the present invention, and the same reference numerals are given to the portions common to the portions shown in FIG. 6 as the third embodiment. This embodiment corresponds to the inventions of claims 9, 11, 12 and claims 16, 19 in addition to the inventions of claims 1, 2, 5, respectively.

  In the eighth embodiment, the diameter expanding excavation step shown in FIG. 31 (B) is exactly the same as that shown in FIG. 6 (B) as the third embodiment. Only the preceding excavation process 31 (A) is different.

  As shown in FIG. 31A and FIG. 32, a diameter D2 having a diameter larger than that of the preceding excavation casing tube 16 having a diameter D1 and a maximum diameter equal to the diameter of the preceding excavation hole H1 is provided at the lower end of the casing tube 16 having the diameter D1. A casing attachment 60 is connected. The casing attachment 60 corresponds to a “second steel pipe” according to claim 9, and the diameter D2 is in a relationship of D3> D2> D1.

  This casing attachment 60 has a so-called cylindrical double tube structure as shown in FIGS. 33 and 34 in addition to FIG. 32, and the inner tube 61 and the outer tube 62 are arranged in a radial shape so that they are concentric with each other. The outer tube 62 extends to a position below the lowermost position of the inner tube 61 while being connected by a single bridge plate 63. The outer diameter of the outer tube 62 is set to a diameter D2 that is equivalent to the diameter of the preceding excavation hole H1 described above. In addition to the bridge plate 63, three radial blades 64 are disposed between the inner tube 61 and the outer tube 62, and these blades 64 have the same height as the lower end position of the outer tube 62. Extends to position. In addition to the lower end of the outer tube 62, a plurality of excavation blades 4 are implanted at the lower end of each blade 64.

  Therefore, according to the eighth embodiment, as shown in FIG. 31A, when the casing attachment 60 is driven to rotate into the ground together with the preceding excavation casing tube 16 by the rotary push-in device 2A. Even if the diameter of the preceding excavation casing tube 16 is D1, the maximum diameter of the casing attachment 60 is D2, and as a result, the preceding excavation hole H1 having the diameter D2 is excavated. Then, as shown by the arrow in FIG. 32, the earth and sand generated by the preceding excavation are gradually gathered in the casing attachment 60, particularly at a position directly below the inner tube 61, and are moved up and down in the preceding excavation casing tube 16. 6 will be dumped.

  31 (B) following the preceding excavation is exactly the same as that shown in FIG. 6 (B), and the preceding excavation hole H1 having the diameter D2 is expanded by the enlarged excavation blade 8. In this way, the shaft H2 having a diameter D3 is finished.

  As shown in FIG. 31 (B), a spiral auxiliary wing 40 similar to that in FIG.

  Also in this eighth embodiment, the diameter of the casing 7 on which the diameter-extended excavation blade 8 is mounted is D1, whereas the diameter of the preceding excavation hole H1 is D2, and between them, Since the gap A of the difference between the diameters D2 and D1 is secured, the earth and sand generated by the diameter expansion excavation by the diameter expansion excavation blade 8 smoothly falls through the gap A and collects at the bottom of the preceding excavation hole H1. Will be. A part of the earth and sand passes through the inside of the casing 7 from the earth and sand intake port 9 of the casing 7 and is collected at the bottom of the preceding excavation hole H1 in the same manner as described above.

  That is, also in the eighth embodiment, the earth and sand generated by the diameter expansion excavation stays in the vicinity of the root portion of the diameter expansion excavation blade 8 as in the prior art, or becomes a compacted state again due to the retention and expands. It will not adhere to the entire diameter excavation blade 8, and the efficiency of taking excavated soil into the bottom side of the preceding excavation hole H1 will be extremely good. Then, the earth and sand collected at the bottom of the preceding excavation hole H1 is discharged by the hammer grab 6 that moves up and down in the casing 7 as described above.

  FIGS. 35 to 37 are views showing a ninth embodiment of the present invention. The diameter expansion excavation step shown in FIG. 28 as the seventh embodiment is the same as the eighth embodiment. The example of the diameter expansion excavation method at the time of using together with the preceding excavation process shown to (A) of 31 is shown.

  That is, in the ninth embodiment, when the caisson 30 is press-fitted and set, the preceding excavation shown in FIG. 31A and the enlarged diameter excavation shown in FIG. The example in the case of excavating under what is called a blade edge (blade edge) is shown. This embodiment corresponds to the inventions described in claims 9, 11, 13 and claims 16, 19, 20 in addition to the inventions described in claims 1, 2, 5 and 6, respectively.

  In this embodiment, as shown in FIG. 35, in addition to excavation inside the caisson 30 prior to press-fitting the caisson 30, all excavation up to excavation under the cutting edge of the caisson 30 that has been press-fitted, that is, the caisson 30 All excavation necessary for the press-in subsidence is performed by using both the pre-excavation shown in FIG. 31A and the diameter-extended excavation shown in FIG. 28. The press-in subsidence of the caisson 30 is advanced as described above. While the press-fitting and excavation are repeated while excavating the earth and sand inside the existing caisson 30 that has been press-fitted, press-fitting and sinking is performed on the existing caisson 30 while adding a so-called ring-cut segment 30a (see FIG. 36). .

  (A) and (B) in FIG. 35 are the preceding excavation process, and as shown in FIG. 35 (A), in addition to the press-fitting and setting device 31 such as the caisson 30 and the hydraulic jack, the rotary push-in device 2A and the preceding excavation casing. When the tube 16 and the like are set on the ground, the preceding excavation hole H1 is excavated to a predetermined depth by pushing it into the ground while rotating the preceding excavation casing tube 16 as shown in FIG.

  When the excavation of the preceding excavation hole H1 is completed, the casing 7 having the diameter expanding excavator 5 is set instead of the preceding excavation casing tube 16 as shown in FIG. Then, as shown in FIG. 4D, the casing 7 is pushed into the ground while being rotationally driven, the inside of the caisson 30 is excavated while expanding the preceding preceding excavation hole H1, and the caisson 30 is Press fit. At this stage, the enlarged diameter excavating blade 8 is in a reduced diameter state.

  If the first-stage caisson 30 is pressed into the ground to some extent, as shown in FIG. 36 (A), after the diameter-extended excavation blade 8 is in an expanded state, as shown in FIG. In addition to the addition of a large caisson 30 (segment 30a), excavation by the enlarged diameter excavating blade 8 as shown in FIG. 30 (segment 30a), and the caisson 30 press-fitting by the diameter-expanded excavating blade 8 and the press-fitting and sinking device 31 as shown in FIG. Thus, the caisson 30 can be press-fitted and set to a predetermined depth.

  After the caisson 30 is press-fitted and settled, the diameter-extended excavator 8 is pulled down to the ground together with the casing 7 after the diameter-excavated blade 8 is reduced in diameter. As a result, a shaft with a predetermined depth is constructed with the caisson 30.

  38 to 40 show a tenth embodiment of the present invention. The same reference numerals are given to the parts common to those shown in FIGS. 35 to 37 as the ninth embodiment.

  In the tenth embodiment, the caisson 30 is excavated by a bucket excavating means 32 such as a clamshell until the first-stage caisson 30 (segment 30a) is press-fitted by the press-fitting and setting device 31. The excavation thereafter is performed in the same procedure as in FIGS.

  That is, as shown in FIGS. 38A and 38B, the caisson 30 (segment 30a) of the first stage is press-fitted by the press-fitting and sinking device 31 while excavating the ground by the bucket excavation means 32, and FIG. After adding the second-stage caisson 30 (segment 30a) as shown in (C), the rotary push-in device 2A and the preceding excavation casing tube 16 are set as shown in FIG.

  Then, as shown in FIG. 39A, the preceding excavation casing tube 16 is pushed into the ground while being rotationally driven, and the preceding excavation hole H1 is excavated to a predetermined depth.

  Thereafter, as shown in FIG. 39 (B), a casing 7 having an enlarged excavator 5 is set in place of the preceding excavation casing tube 16, and thereafter the same as FIG. The caisson 30 is press-fitted and submerged by repeating the diameter-expanded excavation by the diameter-expanding excavator 5 and the press-fitting of the caisson 30 by the press-fitting and substituting device 31 according to the procedures of C), (D) and FIGS. It becomes possible to do.

  After the caisson 30 has been press-fitted and settled, the diameter-extended excavator 5 is pulled out to the ground together with the casing 7 after the diameter-extended excavation blade 8 is reduced in diameter, as in the ninth embodiment. As a result, a shaft with a predetermined depth is constructed with the caisson 30.

  Here, in each of the above-described embodiments, the fixed blade 8a and the movable blade 8b are superposed and arranged as the diameter-excavated excavating blade 8, and the movable blade 8b is slid with respect to the fixed blade 8a. However, since the present invention is not particularly limited to the type of the diameter-expanded drilling blade, instead of the diameter-expanded drilling blade of the previous embodiment, for example, as described above. Of course, it is also possible to employ a diameter-excavated blade of the type described in Patent Documents 2 to 4.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows 1st Embodiment of the diameter expansion excavation system which concerns on this invention, (A) is explanatory drawing of preceding excavation, (B) is explanatory drawing of diameter expanding excavation following the prior excavation of the same figure (A). . Explanatory drawing of an expansion plane of the diameter expansion excavator shown to (B) of FIG. Explanatory drawing which shows 2nd Embodiment of the diameter expansion excavation system which concerns on this invention. Explanatory drawing of an expansion plane of the diameter-excavation machine in FIG. It is a figure which shows the detail of the preceding excavation blade in FIG. 3, (A) is an enlarged front view of the casing attachment for preceding excavation blades, (B) is plane explanatory drawing of the figure (A). It is a figure which shows 3rd Embodiment of the diameter expansion excavation system which concerns on this invention, (A) is explanatory drawing of preceding excavation, (B) is explanatory drawing of diameter expanding excavation following the prior excavation of the figure (A). . FIG. 7 is an enlarged plan view of the preceding excavation blade shown in FIG. The principal part exploded view of the diameter-expansion excavator shown in FIG. Plane | planar explanatory drawing of the diameter expansion excavator shown in FIG. It is a figure which shows the detail in the casing attachment for diameter-enlarged excavation blades in FIG. 8, (A) is the plane explanatory drawing, (B) is front explanatory drawing. FIG. 9 is an enlarged explanatory view of the diameter-excavated excavating blade in FIG. The principal part top view of FIG. The left view of FIG. The rear view of the diameter expansion excavation blade shown in FIG. It is the figure which made the diameter expansion excavation blade of FIG. 12 the diameter reduction state, (A) is the plane explanatory drawing, (B) is front explanatory drawing. Explanatory drawing which shows 4th Embodiment of the diameter expansion excavation system which concerns on this invention. Process explanatory drawing which shows the construction procedure in the system of FIG. Process explanatory drawing which shows the construction procedure following FIG. Process explanatory drawing which shows the construction procedure following FIG. Process explanatory drawing which shows the construction procedure following FIG. Process explanatory drawing which shows the modification of the construction procedure shown to FIGS. Process explanatory drawing which shows the construction procedure following FIG. Process explanatory drawing which shows the construction procedure following FIG. Explanatory drawing which shows 5th Embodiment of the diameter expansion excavation system which concerns on this invention. Process explanatory drawing which shows the construction procedure of the caisson construction in the system of FIG. 24 as the 6th Embodiment of this invention. Process explanatory drawing which shows the construction procedure following FIG. Process explanatory drawing which shows the construction procedure following FIG. Explanatory drawing which shows a diameter expansion excavation process as 7th Embodiment of the diameter expansion excavation system which concerns on this invention. The principal part expansion explanatory drawing of FIG. The bottom view of FIG. Explanatory drawing which shows 8th Embodiment of the diameter expansion excavation system which concerns on this invention. The principal part enlarged view of (A) of FIG. Cross-sectional explanatory drawing which follows the EE line | wire of FIG. Cross-sectional explanatory drawing which follows the FF line of FIG. Process explanatory drawing which shows another construction procedure of caisson construction as the 9th Embodiment of this invention. Process explanatory drawing which shows the construction procedure following FIG. Process explanatory drawing which shows the construction procedure following FIG. Process explanatory drawing which shows another construction procedure of caisson construction as 10th Embodiment of this invention. Process explanatory drawing which shows the construction procedure following FIG. Process explanatory drawing which shows the construction procedure following FIG.

Explanation of symbols

1 ... Casing tube for preceding excavation as third steel pipe (advanced excavating means)
2, 2A ... Rotary push-in device 3 ... Hammer grab (soil removal means)
5 ... Expansion drilling machine (expanding drilling means)
6, 6A ... Hammer grab (soil removal means)
7: Casing as a cylindrical steel pipe (expansion drilling means)
8 ... Diameter drilling blade (Diameter drilling means)
9 ... Sediment uptake port 10 ... Casing attachment for advanced excavation (advanced excavation means)
11 ... Advance excavation blade (advance excavation means)
15 ... Sediment intake port 16 ... Casting tube for advanced excavation (advanced excavation means)
DESCRIPTION OF SYMBOLS 30 ... Caisson 40 ... Spiral auxiliary wing 50 ... Stabilizer as guide means 51 ... Guide ring 60 ... Casing attachment as 2nd steel pipe H1 ... Precise excavation hole H2 ... Expanded excavation hole (stand shaft)
H3 ... Diameter drilling hole

Claims (20)

Including a diameter expanding excavation step for excavating and drilling so as to expand the diameter of the hole excavated in advance in the ground;
In this diameter expansion drilling process,
Drilling to expand the preceding drilling hole with a diameter expanding drilling means provided with a diameter expanding drilling blade on the outer periphery of a cylindrical steel pipe having a diameter smaller than that of the preceding drilling hole. A diameter-expanding excavation method characterized in that the soil is discharged from the steel pipe after being accumulated at the bottom of the preceding excavation hole through a gap between the preceding excavation hole and the steel pipe. Including a preceding excavation step of excavating a preceding excavation hole in the ground with an advance excavation means;
In this advanced excavation process,
The diameter-expanded excavation method according to claim 1, wherein a preceding excavation hole having a diameter larger than the diameter of the steel pipe and smaller than the diameter of the expanded excavation is excavated.   3. The diameter expansion according to claim 2, wherein the diameter excavation means and the preceding excavation means are combined to perform the preceding excavation by the preceding excavation means and the diameter expansion excavation by the diameter expansion excavation means in parallel. Drilling method. The preceding excavation is
The diameter expansion excavation method according to claim 3, wherein the drilling is performed by a prior excavation means provided below a diameter expansion excavation blade in the steel pipe.   3. The diameter expansion drilling method according to claim 2, wherein after the preceding excavation hole is excavated by the preceding excavation means, the diameter expansion excavation is performed by the diameter expansion excavation means instead of the preceding excavation means. In performing the diameter expansion excavation by the diameter expansion excavation means,
A guide means having an outer diameter substantially equal to or smaller than that of the preceding excavation hole is provided at a position below the enlarged diameter excavation blade,
6. The diameter expanding excavation method according to claim 5, wherein the guiding means is inscribed in the preceding excavation hole so that the diameter expanding excavation means is centered with respect to the preceding excavation hole. The preceding excavation is
6. The first and second excavating means, wherein a preceding excavating blade is provided on the outer periphery of a casing tube for preceding excavation having the same diameter as that of the steel pipe on the diameter expanding excavating means side. , 6 The diameter expansion excavation method as described in any one of these.   8. The excavation sediment is taken into the preceding excavation casing tube from the sediment intake port formed in the excavation direction front side of the preceding excavation blade in the preceding excavation blade during the preceding excavation. The diameter-expanding excavation method described in 2. The preceding excavation is
A cylindrical second steel pipe having a diameter substantially the same as the diameter of the preceding drilling hole is mounted on the casing tube for the previous drilling having the same diameter as that of the steel pipe on the side of the expanded drilling means, and a drilling blade is provided at the tip of the second steel pipe. The diameter-expanding excavation method according to any one of claims 1 and 2 and claim 5 and 6, wherein the excavation means is performed by preceding excavation means. The preceding excavation is
It is characterized in that it is carried out by a preceding excavation means in which a drilling blade is attached to the tip of a cylindrical third steel pipe having a diameter larger than that of the steel pipe on the enlarged diameter excavation means side and smaller than the expanded excavation diameter. The diameter expansion excavation method according to any one of claims 1 and 2, and claims 5 and 6.   The diameter expansion excavation method according to claim 1, wherein the diameter expansion excavation blade is capable of expanding and contracting. A spiral auxiliary wing is provided at a position below the expanded diameter drilling blade among the steel pipes forming the expanded diameter drilling means,
The earth and sand excavated by the enlarged diameter excavating blade is pushed into a preceding excavation hole by an auxiliary wing in accordance with excavation rotation of the enlarged diameter excavating blade. Diameter drilling method.   The diameter expansion excavation method according to any one of claims 1 to 12, wherein excavation is performed inside the caisson or under the cutting edge of the caisson. In constructing a shaft with a predetermined depth,
A diameter expansion excavation method, wherein excavation is performed by the method according to claim 3 or 4 over the entire length of the depth of the shaft. In constructing a shaft with a predetermined depth,
5. A diameter-expanding excavation method characterized in that if excavation progresses to the middle of the depth of the shaft, further excavation is carried out by the method according to claim 3 or 4. In constructing a shaft with a predetermined depth,
A diameter-expanding excavation method, wherein excavation is performed by the method according to claim 5 over the entire length of the depth of the shaft. In constructing a shaft with a predetermined depth,
6. A diameter expanding excavation method according to claim 5, wherein if excavation has progressed halfway through the depth of the shaft, deeper excavation is carried out by the method according to claim 5. A diameter expansion excavation system used in the diameter expansion excavation method according to claim 3 or 4,
A diameter-expanding drilling means comprising a diameter-expanded excavating blade on the outer periphery of a cylindrical steel pipe having a smaller diameter than the preceding excavation hole;
A pre-excavation means provided in a position below the diameter-extended excavation blade of the steel pipe, capable of excavating a pre-excavation hole having a diameter larger than that of the steel pipe and smaller than the expanded excavation diameter;
Rotating push means for pushing the steel pipe into the ground while rotating the steel pipe together with the enlarged diameter drilling blade and the preceding excavation means,
A soil removal means for moving up and down in the steel pipe and grabbing the earth and sand in the steel pipe, and then discharging it outside the steel pipe;
An enlarged diameter drilling system characterized by comprising: A diameter expansion excavation system used in the diameter expansion excavation method according to claim 5 or 6,
A diameter-expanding drilling means comprising a diameter-expanded excavating blade on the outer periphery of a cylindrical steel pipe having a smaller diameter than the preceding excavation hole;
A preceding excavation means capable of excavating a preceding excavation hole having a diameter larger than that of the steel pipe and smaller than an expanded excavation diameter;
Rotating push-in means for pushing the steel pipe into the ground while rotating the steel pipe together with the enlarged diameter excavating blade after gripping the steel pipe,
A soil removal means for moving up and down in the steel pipe and grabbing the earth and sand in the steel pipe, and then discharging it outside the steel pipe;
An enlarged diameter drilling system characterized by comprising: A diameter expansion excavation system used for the diameter expansion excavation method according to claim 6,
A diameter-expanding drilling means comprising a diameter-expanded excavating blade on the outer periphery of a cylindrical steel pipe having a smaller diameter than the preceding excavation hole;
A preceding excavation means capable of excavating a preceding excavation hole having a diameter larger than that of the steel pipe and smaller than an expanded excavation diameter;
Rotating push-in means for pushing the steel pipe into the ground while rotating the steel pipe together with the enlarged diameter excavating blade after gripping the steel pipe,
The steel pipe is provided at a position lower than the enlarged drilling blade and has an outer diameter that is substantially the same as or smaller than that of the preceding drilling hole. Guiding means for guiding the diameter excavating means to be centered;
A soil removal means for moving up and down in the steel pipe and grabbing the earth and sand in the steel pipe, and then discharging it outside the steel pipe;
An enlarged diameter drilling system characterized by comprising:

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