Drilling apparatus and drilling method

Abstract

The object of the present invention is to solve the problems of the prior art, namely, to provide a drilling device that is lighter than the weight of the test equipment of the prior art and has higher drilling capacity than the technology of Patent Document 1, and a drilling method using the same. [Solution] The drilling device of the present invention is a device for drilling holes in the ground using a core drill, and comprises a drilling column, a slider, a core drill, a reduction gear, and a rod. The slider is mounted to move in the axial direction of the drilling column, which is positioned substantially vertically, and the core drill is attached to the slider. The reduction gear is connected to the rotation axis of the core drill, and the rod is connected to the reduction gear. The reduction gear transmits rotation to the rod at a rotation speed lower than the rotation speed input from the rotation axis of the core drill.

Description

Technical Field

[0001] The present invention relates to boring surveys of the ground, and more specifically, to a boring device for boring the ground using a core drill and a method for boring the ground using the same.

Background Art

[0002] Transmission towers are one of the extremely important facilities for stably supplying power to consumers. Naturally, they have a robust structure and, in principle, settlement (especially uneven settlement) is not allowed. Therefore, important and heavy structures such as transmission towers are constructed on a supporting layer where a considerable bearing capacity can be expected, such as bedrock or compacted sand layers. For example, in the case of a transmission tower, it is often structured such that a foundation is constructed on the supporting layer and leg members are fixed to the foundation. That is, a form of obtaining support from the supporting layer through the foundation is common.

[0003] When the supporting layer is at a relatively shallow position, it is possible to excavate to a predetermined depth to expose the supporting layer and directly construct a foundation (so-called "direct foundation") on this supporting layer. On the other hand, when the supporting layer is at a relatively deep position, a considerable amount of excavation is required to expose the supporting layer, and furthermore, the construction of a large-scale foundation is necessary, making a direct foundation unrealistic. Therefore, in such cases, a "pile foundation" is adopted instead of a direct foundation.

[0004] In order to compare and consider a direct foundation and a pile foundation, or to plan and design a direct foundation or a pile foundation, it is necessary to grasp the depth of the supporting layer and the geology (rock quality). Usually, a standard penetration test defined by Japanese Industrial Standards (JIS A 1219) is conducted. The standard penetration test is an in-situ test that measures the N value every 1 m while excavating (boring) a test hole and collects samples (cores). A striking device (hammer, guide rod, anvil, dropping means, etc.), a boring rod, a sampler, an excavating device (usually a rotary boring machine), a tripod, a frame, etc. are used.

[0005] As such, the standard penetration test requires various equipment and devices, and some of them, such as the rotary boring machine (approximately 300 kg), are relatively heavy. Therefore, transportation to the site is often an obstacle to conducting the test. In particular, in the case of power transmission towers, they are sometimes installed in mountainous areas with no traffic of people or vehicles, meaning that roads and other access routes to the site are not in place, making the transportation of equipment for the standard penetration test a major obstacle. If the total weight of the equipment is not too great, it can be transported by engine-driven crawlers, but in the case of the standard penetration test, the total weight of the equipment exceeds 1 ton, so such transportation is not feasible.

[0006] Traditionally, transporting equipment for standard penetration tests to test sites inaccessible to vehicles involved constructing temporary transport facilities such as monorails or cableways, and using these facilities to transport the equipment in small quantities. However, constructing monorails or cableways required considerable effort and cost, and considering the effort and cost of removal, they were often left in place until the test equipment was removed. As a result, the depreciation costs associated with the monorails and cableways also increased the overall cost of the operation.

[0007] Patent Document 1 proposes a test apparatus and test method with a reduced total weight (290 kg). Specifically, it is a technique for drilling a test hole using only hammer strikes, that is, a technique for performing a penetration test without using a boring machine. This makes it possible to measure the N value (NP value) and take core samples, so to speak, to perform a test that conforms to the standard penetration test. Moreover, as a result of reducing the weight of the test equipment, it can be transported by an engine-driven crawler, thus avoiding the construction of a monorail or similar structure. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Patent No. 6619235 [Overview of the project] [Problems that the invention aims to solve]

[0009] The technology disclosed in Patent Document 1 allows for the implementation of tests similar to standard penetration tests without the need to construct monorails or the like, thus at low cost. However, because it does not use a rotary boring machine, its drilling capacity is somewhat inferior to conventional technologies. With the technology of Patent Document 1, for example, it is difficult to drill into ground where layers with an N-value of 50 or higher are continuous for 2 meters or more, and the drilling depth is generally limited to about 20 meters.

[0010] Incidentally, depending on the type of rock in the ground being tested (for example, granite), core stones (boulders or pebbles) may be present, and if these core stones are found at the drilling location, continuous drilling through a hard layer (for example, a layer with an N value of 50 or higher) becomes unavoidable. Furthermore, when using pile foundations, it is not uncommon for the supporting layer to be at a depth of 20m or more. In other words, in such cases, it is not possible to conduct investigations using the technology described in Patent Document 1. However, if conventional technology is adopted, the construction of monorails, etc., becomes unavoidable, and the cost of testing and the working time must be accepted.

[0011] Therefore, the inventors of the present invention came up with the idea of ​​drilling a test hole using a relatively lightweight core drill. This core drill is equipped with an electric motor, which causes the rotating shaft (drill shaft) to rotate at high speed. Normally, core drills are fitted with a cylindrical core bit equipped with a diamond bit and are used to take cores from concrete structures, stone materials, etc. That is, the core bit rotates together with the rotating shaft of the core drill to drill a hole in the concrete, and as the drilling progresses, a concrete core is taken into the core bit.

[0012] As mentioned above, core drills are relatively lightweight and rotate at high speeds. For example, the "Dymo Drill (registered trademark) TS-165" manufactured by Shibuya Co., Ltd. rotates at 1000 / 700 rpm and weighs 15.5 kg, while the "Dymo Drill TS-405" rotates at 700 / 300 rpm and weighs 30.9 kg. On the other hand, considerable torque is required to drill into the ground, and therefore the drilling rod is rotated at a relatively low speed. For example, conventional rotary boring machines rotated the drilling rod at around 100-50 rpm. In other words, when using a core drill, the drilling rod rotates at such high speed that there is a risk that the ground cannot be drilled properly. In fact, when the inventors conducted experiments, they confirmed that the rotation of the drilling rod sometimes stopped during drilling, and they also detected that the core drill vibrated violently during drilling, which could endanger the worker.

[0013] The object of the present invention is to solve the problems of the prior art, namely, to provide a drilling device that is lighter than the weight of the test equipment of the prior art and has higher drilling capacity than the technology of Patent Document 1, and a drilling method using the same. [Means for solving the problem]

[0014] The present invention focuses on the fact that by combining a core drill and a reduction gear, the rod is rotated at a rotational speed lower than the rotational speed input from the core drill, that is, at a torque higher than the torque input from the core drill, while drilling a test hole. This invention is based on an unprecedented idea.

[0015] The drilling apparatus of the present invention is a device for drilling holes in the ground using a core drill, and comprises a drilling column, a slider, a core drill, a reduction gear, and a rod. The slider is mounted to move in the axial direction of the drilling column, which is positioned with its axial direction approximately vertical (including vertical), and the core drill is attached to the slider. The reduction gear is connected to the rotation axis of the core drill, and the rod is connected to the reduction gear. The reduction gear transmits rotation to the rod at a rotation speed lower than the rotation speed input from the rotation axis of the core drill.

[0016] The drilling device of the present invention may further include a reduction gear for a planetary gear mechanism. This planetary gear mechanism consists of a sun gear, a plurality of planetary gears, planetary carriers connected to these planetary gears, and an internal gear. In this case, the rotating shaft is directly (or indirectly via a connecting jig) connected to the sun gear, and the rod is directly (or indirectly via a connecting jig) connected to the planetary carriers. The plurality of planetary gears are arranged inside the internal gear, whose rotation is restricted, so as to mesh with the internal gear and the sun gear. As a result, the planetary carriers rotate at a rotational speed lower than the rotational speed of the sun gear.

[0017] The drilling device of the present invention may also be configured such that a left arm and a right arm are attached to the reduction gear. In this case, the oscillation of the reduction gear can be suppressed by clamping the slider (or core drill) between the left arm and the right arm.

[0018] The drilling apparatus of the present invention may further include a water swivel and a water injection ring. The water swivel is hollow and has a water passage hole on its side, and the water injection ring has a water injection hole on its side and is fitted onto the water swivel. The water swivel is connected to a speed reducer and also to a rod, and rotates together with a part of the speed reducer to transmit rotation to the rod. The water injection ring is fixed to a part of the speed reducer to restrict its rotation. Water pressurized from the water injection hole is supplied to the inside of the water swivel through the water passage hole.

[0019] The drilling apparatus of the present invention may also be configured such that a sliding rack arranged along the axial direction is provided on the drilling column, and a sliding gear is provided on the slider. In this case, the slider moves along the core drill in the axial direction of the drilling column by a rack and pinion mechanism consisting of the sliding rack and the sliding gear.

[0020] The drilling method of the present invention is a method for drilling ground using the drilling apparatus of the present invention, and comprises a column installation step, an equipment installation step, and a rod rotation step. In the column installation step, a drilling column is installed on the ground so that its axial direction is approximately vertical (including vertical). In the equipment installation step, a slider to which a core drill is attached is attached to the drilling column, a reduction body is connected to the rotation axis of the core drill, and a rod is connected to the reduction body. In the rod rotation step, the rod is rotated by rotating the rotation axis with the core drill. In the rod rotation step, the rod rotates at a rotation speed smaller than the rotational speed input from the rotation axis, and with a torque larger than the torque input from the rotation axis, and a test hole is formed in the ground as the rod rotates.

[0021] The drilling method of the present invention can also be a method of rotating a rod to which a core tube is connected at its lower end. In this case, during the rod rotation process, drilling is performed while taking a core sample from the core tube.

[0022] The drilling method of the present invention may further include a drilling device movement step and a testing step. In this drilling device movement step, after drilling to a predetermined depth by a rod rotation step, the drilling device is moved to a position away from the test hole, and in the testing step, an in-situ test of the ground is performed after the drilling device movement step. [Effects of the Invention]

[0023] The drilling apparatus and drilling method of the present invention have the following effects. (1) Since it is lighter than the conventionally used boring machine (about 300 kg), for example, even in the case of transporting equipment to a test site in mountainous areas, it can be transported by an engine-driven crawler or the like without constructing temporary facilities for transportation such as a monorail or a cableway. As a result, the labor and cost involved in temporary facilities and equipment transportation can be reduced, and the period required for the entire operation can also be shortened. (2) By combining a core drill and a speed reducer, it has a higher drilling ability than the "lightweight ground investigation machine" disclosed in Patent Document 1. As a result, continuous drilling (for example, continuous drilling of 2 m or more) of a hard layer including core stones (for example, a layer with an N value of 50 or more) is possible, and it is also possible to drill to a support layer at a depth of 20 m or more. (3) Since the rod for drilling is rotated at a low speed (about 100 to 50 rpm), the rod can appropriately drill the ground in a stable state, and the core drill does not vibrate violently during drilling, so that the operator can work safely.

Brief Description of the Drawings

[0024] [Figure 1] Side view showing the drilling device of the present invention. [Figure 2] Side view showing the drilling means constituting the drilling device. [Figure 3] Side view schematically showing a core drill attached to a slider. [Figure 4] (a) is a cross-sectional view showing the speed reducer in an assembled state, and (b) is an exploded view showing each part constituting the speed reducer. [Figure 5] Plan view schematically showing a speed reducer main body using a planetary gear mechanism. [Figure 6] Perspective view schematically showing a speed reducer provided with a stopper mechanism composed of a left arm, a right arm, and a connecting bar. [Figure 7] Perspective view schematically showing a water swivel. [Figure 8] Side view showing a state in which a hole support column is rotated by a rotation mechanism constituting the drilling means. [Figure 9]A schematic side view illustrating the rotation mechanism. [Figure 10] (a) is a schematic side view showing each part that constitutes the support column mechanism, and (b) is a side view showing the situation in which the support column mechanism connected to the test column supports the drilling column. [Figure 11] A flowchart showing the main steps of the drilling method of the present invention. [Modes for carrying out the invention]

[0025] An example of an embodiment of the drilling apparatus and drilling method of the present invention will be described with reference to the figures.

[0026] 1. Drilling equipment First, the drilling apparatus of the present invention will be explained with reference to the diagram. The drilling method of the present invention is a method of drilling the ground using the drilling apparatus of the present invention. Therefore, the drilling apparatus of the present invention will be explained first, and then the drilling method of the present invention will be explained.

[0027] Figure 1 is a side view (cross-sectional view for underground) of the drilling device 100 of the present invention. As shown in this figure, the drilling device 100 of the present invention is configured to include a "drilling means 200" that drills into the ground to form a hole (hereinafter referred to as "test hole TH"), and can also be configured to include a "test means 300" that uses this test hole TH to conduct a ground test. The drilling means 200 is positioned on one side of the test hole TH, and the test means 300 is positioned on the other side. For convenience, the direction in which the drilling means 200 and the test means 300 are aligned as shown in Figure 1 will be referred to as the "transverse direction," and the side of the transverse direction on which the drilling means 200 is located will be referred to as the "front," and the side on which the test means 300 is located will be referred to as the "rear." The drilling means 200 and the test means 300 will be described in order below.

[0028] 1-1. Drilling means Figure 2 is a side view (cross-sectional view for underground) of the drilling means 200 that constitutes the drilling device 100 of the present invention. As shown in Figures 1 and 2, the drilling means 200 is composed of a drilling column 201, a slider 202, a core drill 203, a reduction body 204, and a drilling rod 205, and can further be composed of a core tube 206, a column support means 207, a water supply mechanism 208 (described later), a rotating mechanism 209, a base 400, etc. The main elements constituting the drilling means 200 will be described in detail below.

[0029] (base) The base 400 is formed by assembling steel materials and is usually installed on the ground. This base 400 is the foundation that supports the drilling means 200 and the testing means 300, and is therefore firmly fixed to the ground using anchor materials that can be driven into the ground (hereinafter referred to as "base anchors 401"). For example, in Figure 1, multiple base anchors 401 are driven in until sufficient embedment is achieved, and the base 400 is connected and fixed to the multiple base anchors 401 using clamps, etc. When drilling at a test site where it is difficult to transport each component, it is advisable to make the base 400 a structure consisting of multiple parts, and to assemble each part on-site after it has been transported individually.

[0030] (Drilling support) The drilling support column 201, which constitutes the drilling means 200, is a hollow or solid columnar member, and its legs are fixed to the base 400. When drilling is performed by the drilling means 200, the column axis is approximately vertical (including the vertical). By providing a rotation mechanism 209, which will be explained in detail later, the drilling support column 201 can also be fixed to the base 400 at its legs so that it rotates around an approximately horizontal (including the horizontal) axis, that is, in an approximately vertical plane (including the vertical plane). Of course, depending on the conditions of the test site, the drilling support column 201 can also be fixed to the base 400 without providing the rotation mechanism 209, that is, with rotation constrained.

[0031] (slider) The slider 202, which constitutes the drilling means 200, is attached to the drilling column 201 and also supports the core drill 203. In other words, the core drill 203 is attached to the drilling column 201 via the slider 202. However, the slider 202 is attached to the drilling column 201 so that it can slide along the column axis direction (i.e., vertical direction) of the drilling column 201. As a result, the core drill 203 can slide downward without any particular resistance even as drilling progresses.

[0032] Various conventional techniques can be used to move the slider 202 along the column axis direction of the drilling column 201. For example, the slider 202 can be moved by a combination of a chain and pulley, or by a combination of a motor and tires. Alternatively, as shown in Figure 2, a rack and pinion mechanism consisting of a sliding rack 201A and a sliding gear 202A can be used. The sliding rack 201A is attached to the front side (right side in the figure) of the drilling column 201 along the column axis direction (i.e., vertical direction), and the sliding gear 202A is attached to the slider 202. Then, with the sliding gear 202A meshed with the sliding rack 201A, the slider 202 is moved by operating the lever block (registered trademark) 202B shown in Figure 3.

[0033] (Core drill) Figure 3 is a side view showing the core drill 203, which constitutes the drilling means 200, attached to the slider 202. This core drill 203 includes a motor driven by electricity and a rotating shaft (hereinafter referred to as "drill rotating shaft 203A") that rotates at high speed by this motor. It can be manufactured as a dedicated unit, or a product already available on the market (commercially sold or leased) can be used. For example, the "Dymo Drill TS-165" or "Dymo Drill TS-405" manufactured by Shibuya Co., Ltd. can be used. However, a commonly used core bit is not used, and a reduction gear 204 is connected to the drill rotating shaft 203A.

[0034] (Deceleration body) Figure 4 shows the reduction gear 204 that constitutes the drilling means 200, where (a) is a cross-sectional view showing the assembled parts and (b) is an exploded view showing the parts that make up the reduction gear 204. As shown in this figure, the reduction gear 204 is composed of a reduction gear body 204A, and can also be composed of an upper flange 204B, a lower flange 204C, a coupler 204D which is a connecting jig, a water supply mechanism 208, etc. Of these, the water supply mechanism 208 supplies drilling water injected from the outside into the drilling rod 205, as will be described later, and is composed of a water swivel 208A and a water injection ring 208B.

[0035] The upper flange 204B and lower flange 204C stably support the reducer body 204A by clamping it from above and below. Part of the reducer body 204A rotates together with the drill rotation shaft 203A, but the rotation is restricted by the upper flange 204B and lower flange 204C. Although Figure 4 uses a single-stage reducer body 204A, it is not limited to this configuration and two or more stages of reducer bodies 204A can be stacked and used. The coupler 204D, which is inserted into the upper flange 204B, is connected to the drill rotation shaft 203A at its upper end and to the reducer body 204A at its lower end. However, depending on the structure of the drill rotation shaft 203A, it is also possible to connect the drill rotation shaft 203A directly to the reducer body 204A without using the coupler 204D.

[0036] The gearbox body 204A reduces the rotation of the drill shaft 203A and then transmits the rotation to the lower rotating system (water swivel 208A, drilling rod 205, core tube 206, etc.). As previously described, the core drill 203 rotates the drill shaft 203A at a high rotational speed (revolutions per unit time). For example, the Dymo Drill TS-165 has a rotational speed of 1000 / 700 rpm, and the Dymo Drill TS-405 has a rotational speed of 700 / 300 rpm. However, if the rotation is transmitted to the drilling rod 205 at high speed, sufficient torque cannot be obtained, especially when drilling hard ground. Therefore, the gearbox body 204A reduces the rotation and transmits a rotation with a large torque. In other words, the reduction gear body 204A transmits rotation to the drilling rod 205, etc., at a rotational speed lower than the rotational speed input from the drill rotation shaft 203A, and with a torque greater than the torque input from the drill rotation shaft 203A.

[0037] As long as the reduction gear body 204A can reduce the rotation of the drill rotation shaft 203A and transmit that rotation to the lower rotation system, various conventional reduction gears can be used. For example, a reduction gear body 204A using the planetary gear mechanism shown in Figure 5 can be adopted. In this case, the reduction gear body 204A consists of a sun gear GS, multiple (four in the figure) planetary gears GP, an internal gear GR, and a planetary carrier (not shown), as shown in the figure, with the sun gear GS and planetary gears GP positioned inside the internal gear GR. The planetary gears GP are also positioned to mesh with the gears of the internal gear GR and the sun gear GS, respectively. A coupler 204D connected to the drill rotation shaft 203A is connected to the sun gear GS, and the planetary carriers connected to the multiple planetary gears GP are connected to the drilling rod 205. As mentioned above, it is also possible to directly connect the drill rotation shaft 203A to the sun gear GS without using the coupler 204D. Alternatively, instead of directly connecting the planetary carrier to the drilling rod 205, as shown in Figure 4, the planetary carrier can be connected to a water swivel 208A (connecting jig), and the drilling rod 205 can then be connected to the lower part of the water swivel 208A.

[0038] The internal gear GR is fixed in such a way that its rotation is constrained (restricted). On the other hand, the sun gear GS rotates in conjunction with the rotation of the drill rotation shaft 203A, and the planetary gear GP and planetary carrier also rotate in conjunction with the rotation of the sun gear GS. As a result, the planetary carrier rotates at a rotational speed lower than the rotational speed input from the drill rotation shaft 203A, and consequently, the drilling rod 205 also rotates at a lower speed than the drill rotation shaft 203A.

[0039] Although the core drill 203 rotates at high speed, it is supported by the slider 202, so no large oscillations occur. On the other hand, the reduction gear 204 is only connected to the drill rotation shaft 203A, and it is possible that it may oscillate significantly with the high-speed rotation of the core drill 203, which could endanger the operator. Therefore, in cases where large oscillations of the reduction gear 204 are expected, it is advisable to provide a stopper mechanism on the reduction gear 204. For example, in Figure 6, a stopper mechanism consisting of a left arm 204E, a right arm 204F, and a connecting bar 204G is provided on the reduction gear 204. The left arm 204E and the right arm 204F are fixed to a part of the reduction gear 204 (for example, the internal gear GR, the upper flange 204B, and the lower flange 204C) so as to extend upward, and the connecting bar 204G, positioned between them, connects and supports the left arm 204E and the right arm 204F. Then, by sandwiching the slider 202 and core drill 203 between the left arm 204E and the right arm 204F, the oscillation of the reduction gear 204 is suppressed.

[0040] (Drilling rod) The drilling rod 205 that constitutes the drilling means 200 is a rod that has been conventionally used in boring and other applications, and products that are already available on the market (commercially sold or leased) can be used. As described above, the upper part of the drilling rod 205 can be directly connected to a part of the reduction gear 204 (for example, the planetary carrier), or it can be indirectly connected to a part of the reduction gear 204 (for example, the planetary carrier) via a coupler or water swivel 208A as a connecting jig. In addition, it is possible to drill into the ground with a bit attached to the tip of the drilling rod 205, or to drill into the ground while collecting ground samples (cores) by attaching a core tube 206 to the tip of the drilling rod 205.

[0041] (Water supply mechanism) The water supply mechanism 208, which constitutes the drilling means 200, supplies drilling water to the drilling rod 205 during drilling, and is composed of a water swivel 208A and a water injection ring 208B. The hollow, generally columnar water swivel 208A is connected to a part of the reduction body 204 (e.g., a planetary carrier) and rotates together with the drill rotation shaft 203A, transmitting rotation to the drilling rod 205 connected at its lower end. In contrast, the annular water injection ring 208B is connected to a part of the reduction body 204 (e.g., a lower flange 204C) and its rotation is restricted.

[0042] Figure 7 is a schematic perspective view of the water swivel 208A. As shown in this figure, a water passage hole WP is provided on the side of the water swivel 208A. The water swivel 208A also has a ring-shaped water retention groove GT that is slightly recessed from the surrounding side, and the water passage hole WP is provided within this water retention groove GT. In other words, the water passage hole WP opens at a position slightly recessed from the side. On the other hand, as shown in Figure 4(a), a water injection hole WE is provided on the side of the water injection ring 208B. This water injection ring 208B is extrapolated onto the water swivel 208A so as to cover the water retention groove GT, and as a result, a donut-shaped closed space (hereinafter referred to as the "water storage space") is formed by the inner wall of the water injection ring 208B and the water retention groove GT.

[0043] The mechanism by which drilling water is supplied to the drilling rod 205 during drilling is described below. When water is pumped from a water tank using a submersible pump or the like, it is sent into the water injection ring 208B through the water injection hole WE connected to a hose or the like. Next, the water flows through the side wall of the water injection ring 208B and is sent into the water swivel 208A, where it is stored in the water reservoir. Then, water entering from the water passage hole WP flows through the water swivel 208A and is supplied to the drilling rod 205 as drilling water. At this time, water is stored in the water reservoir, so water is always supplied to the water passage hole WP even while the water swivel 208A is rotating, and therefore drilling water is always supplied to the drilling rod 205 during drilling. Note that in cases where so-called "waterless drilling," where no drilling water is used, is possible, the drilling means 200 does not necessarily need to be equipped with a water supply mechanism 208.

[0044] (Rotation mechanism) Figure 8 is a side view (cross-sectional view for underground) showing the drilling column 201 rotated by the rotating mechanism 209 that constitutes the drilling means 200, and Figure 9 is a schematic partial side view showing an example of the rotating mechanism 209. As shown in this figure, the rotating mechanism 209 rotates the drilling column 201 around a substantially horizontal (including horizontal) axis, that is, within a substantially vertical plane (including the vertical plane), and in particular can rotate the drilling column 201 with the slider 202 and core drill 203 attached. As shown in Figure 8, when the drilling column 201 is rotated around a substantially horizontal axis, or more specifically, when the drilling column 201 is rotated so that it tilts forward, the drilling means 200 moves to a position away from the test hole TH, so that the test means 300 can perform an in-situ test of the ground using the test hole TH. In other words, thanks to the effect of having a rotating mechanism 209, it is possible to easily transition to an in-situ test simply by rotating the drilling column 201.

[0045] When rotating the drilling column 201, various conventional techniques can be used, such as using a winch or a lever block (registered trademark). Alternatively, a rotation mechanism 209 as shown in Figure 9 can be adopted. The rotation mechanism 209 shown in this figure is equipped with a support plate 209A having an arc-shaped guide groove GH formed therein, and a connecting jig 209B consisting of a combination of bolts and nuts. This support plate 209A is fixed to a base 400, for example, and one of the drilling columns 201 is pin-connected to the base 400 or support plate 209A at its lower end. The drilling column 201 is also provided with bolt holes at positions corresponding to the guide groove GH. When the drilling column 201 is rotated after inserting bolts (connecting jig 209B) through the bolt holes and guide groove GH, the drilling column 201 can rotate while being guided by the guide groove GH. Furthermore, by rotating the drilling support column 201 by a desired inclination angle (e.g., 45 degrees) and then screwing a nut (connecting jig 209B) onto the bolt (connecting jig 209B) and tightening it, the inclination angle of the drilling support column 201 can be maintained. In other words, the connecting jig 209B (bolt and nut) that clamps and tightens the drilling support column 201 and the support plate 209A functions as a stopper to support the inclined drilling support column 201.

[0046] (Strut support means) As shown in Figure 2, the drilling means 200 can drill with the drilling column 201 standing upright. On the other hand, if the core drill 203 rotates at a considerably high speed, the drilling column 201 may oscillate during drilling, resulting in wobble in the drilling rod 205, which may prevent the formation of a proper test hole TH, or even create a situation where the worker is in danger. In such cases, it is preferable to support the drilling column 201 during drilling with the column support means 207, as shown in Figure 1.

[0047] Figure 10 is a schematic diagram of the support column means 207 that constitutes the drilling means 200, where (a) is a side view showing the individual parts of the disassembled support column means 207, and (b) is a side view showing the situation in which the support column means 207 connected to the test column 301 supports the drilling column 201. The support column means 207 shown in this figure consists of a first arm 207A and a second arm 207B, with one end of the first arm (right end in the figure) and one end of the second arm 207B (left end in the figure) being pin-connected. The other end of the first arm 207A (left end in the figure) is pin-connected to the test column 301. As a result, the first arm 207A rotates around a substantially horizontal (including horizontal) axis, and the second arm 207B also rotates around a substantially horizontal (including horizontal) axis. Therefore, unless any special operation is performed, the first arm 207A and the second arm 207B will be in a state of hanging vertically downward, as shown in Figure 8.

[0048] On the other hand, when the drilling column 201 is supported by the support column support means 207, as shown in Figure 10(b), the first arm 207A is rotated to be positioned approximately horizontal (including horizontal), and the second arm 207B is rotated to be positioned approximately vertical (including vertical) downward. Then, the narrow diameter portion formed at the lower end of the second arm 207B is inserted into the upper part of the drilling column 201. In this way, the drilling column 201 is supported by the support column support means 207, and even when the core drill 203 rotates at a considerably high speed, the oscillation of the drilling column 201 during drilling can be suppressed.

[0049] 1-2. Test Methods Next, the test means 300 that constitute the drilling apparatus 100 of the present invention will be described. This test means 300 can perform various in-situ tests such as conical penetration tests, Swedish sounding tests, vane tests, and in-hole loading tests, but for convenience, the example in which the test means 300 performs a standard penetration test will be described here.

[0050] As shown in Figure 8, the test means 300 consists of a test support 301, a guide rod 307, a hammer 308 (drive hammer), a knocking head 309 (anvil), a test rod 310, and a sampler 311. It can also be further composed of a pulley beam 302, a rope 304, a winch with a pulley 305, a small engine 306, a rod puller, a counterweight, and the like.

[0051] The test support column 301, which constitutes the test means 300, is a hollow or solid columnar member, with its axis approximately vertical (including vertical) and its legs fixed to the base 400. A pulley beam 302, positioned approximately horizontally (including horizontal), is attached to the top of the test support column 301, and pulleys 303 are provided at its front and rear. A rope or other material 304 is wound around the front and rear pulleys 303, and a hammer 308 (especially a catcher) is attached to the lower front end (right side in the diagram) of the rope 304, while the lower rear end (left side in the diagram) is wound around the pulley of a pulley-equipped winch 305. This pulley-equipped winch 305 winds in and out the rope 304, and a small engine 306 powers the pulley-equipped winch 305. The rod extraction machine uses a hydraulic jack or the like to extract the test rod 310 and the drilling rod 205. The drilling device 100 of the present invention can also employ a conventionally used three-pronged rig instead of the temporary equipment described above.

[0052] The guide rod 307, hammer 308, knocking head 309, test rod 310, and sampler 311 that constitute the test means 300 can be equipment specified in "JIS A 1219". Of these, the guide rod 307 is supported by an arm installed on the test support column 301, with the column axis being approximately vertical (including vertical). The hammer 308 is inserted through the guide rod 307, and the knocking head 309 is attached to its lower end. The test rod 310 is attached below the knocking head 309, and the sampler 311 is attached to the lower end of the test rod 310.

[0053] The procedure for performing a standard penetration test using the test means 300 is described below. First, drilling is performed using the drilling means 200, and once the test hole TH is formed to a predetermined depth, the drilling rod 205 is pulled out, for example, by a rod puller, and the drilling means 200 is moved to a position away from the test hole TH. At this time, if the drilling means 200 is equipped with a rotating mechanism 209, it can be easily moved by simply rotating the drilling support column 201.

[0054] When the drilling device 200 is moved, preparations for the standard penetration test are made. Specifically, the hammer 308 is inserted through the guide rod 307, and a knocking head 309 is attached to its lower end. A test rod 310 is attached below the knocking head 309, and a sampler 311 is attached to the lower end of the test rod 310. The sampler 311 is then lowered to the bottom of the test hole TH and allowed to sink on its own. A "preliminary run" is performed in which the 63.5 kg hammer 308 is repeatedly dropped from a height of 760 mm ± 10 mm until the sampler 311 penetrates 150 mm. After the preliminary run, a "main run" is performed in which the 63.5 kg hammer 308 is repeatedly dropped from a height of 760 mm ± 10 mm until the sampler 311 penetrates 300 mm, and the N value is recorded every 100 mm of depth. After the sampler 311 penetrates 300 mm, a 5 cm "post-penetration" is performed, the sampler 311 is withdrawn, the shoe and coupling are removed, and the split barrel is cut in two to observe the collected sample, and a representative sample is stored in a transparent container. Then, drilling is performed again with the drilling means 200 to form the test hole TH, the drilling means 200 is moved, and the standard penetration test is performed.

[0055] 2. Drilling Method Next, the drilling method of the present invention will be explained with reference to Figure 11. The drilling method of the present invention is a method of drilling the ground using the drilling device 100 described so far. Therefore, explanations that overlap with those described for the drilling device 100 will be avoided, and the explanation will mainly focus on the aspects specific to the drilling method of the present invention. In other words, anything not described here is the same as what was described in "1. Drilling Device".

[0056] Figure 11 is a flowchart showing the main steps of the drilling method of the present invention. As shown in this figure, first a base 400 is installed on the ground (Step 10 in Figure 11), the drilling means 200 is assembled (Step 20 in Figure 11), and a part of the testing means 300 is assembled (Step 30 in Figure 11). When assembling the drilling means 200, a drilling support column 201 with a column axis that is approximately vertical is fixed to the base 400 at its legs (Step 21 in Figure 11), a slider 202 with a core drill 203 attached is attached to the drilling support column 201, a reduction body 204 is attached to the core drill 203, and then a drilling rod 205 and a core tube 206 are attached (Step 22 in Figure 11).

[0057] On the other hand, when assembling the test device 300, the test support column 301, whose column axis is approximately vertical, is fixed to the base 400 at its legs (Step 31 in Figure 11). Next, a winch with pulley 305, a small engine 306, a rod puller, a counterweight, etc. are installed on the base 400, and the rope material 304 is wound around the pulley of the winch with pulley 305, and then wound around the pulley 303 of the pulley beam 302 (Step 32 in Figure 11). At this time, it is advisable to attach a guide rod 307 to the arm installed on the test support column 301.

[0058] After assembling the drilling means 200 and the testing means 300, drilling is performed by the drilling means 200 to form a test hole TH to a predetermined depth (Step 40 in Figure 11). Then, for example, the drilling rod 205 is pulled out using a rod puller, and the drilling means 200 is moved to a position away from the test hole TH (Step 50 in Figure 11). At this time, if the drilling means 200 is equipped with a rotating mechanism 209, it can be easily moved by simply rotating the drilling support column 201.

[0059] As the drilling mechanism 200 is moved, the hammer 308 is inserted through the guide rod 307, and the hammer 308 (especially the catcher) is attached to the lower end of the guide rod 304. Then, the knocking head 309 is attached to the lower end of the guide rod 307, the test rod 310 is attached below the knocking head 309, and the sampler 311 is attached to the lower end of the test rod 310 (Step 60 in Figure 11). Once these preparations are complete, a standard penetration test is performed over one section (usually 50 cm) (Step 70 in Figure 11).

[0060] The work is terminated when the test borehole TH reaches the planned depth or when the planned supporting ground is confirmed (Yes in Step 80 of Figure 11). On the other hand, when conducting a standard penetration test at a deeper location (No in Step 80 of Figure 11), the series of steps consisting of drilling one section (Step 40) to conducting a standard penetration test for one section (Step 70) is repeated. [Industrial applicability]

[0061] The drilling apparatus and drilling method of the present invention can be used in standard penetration tests to understand the conditions of the ground (determination of ground hardness, compaction, and soil layer composition), and can be particularly effective in standard penetration tests conducted in locations where it is difficult to transport equipment, such as test sites in mountainous areas. [Explanation of Symbols]

[0062] 100 Drilling apparatus of the present invention 200 Drilling means (of drilling equipment) 201 Drilling support (for drilling means) 201A (Drilling support) sliding rack 202 Slider (of drilling means) 202A (Slider) Gear for Slide 202B (Slider) Lever Block (Registered Trademark) 203 Core drill (for drilling) 203A (Core drill) Drill rotation shaft 204 (Drilling mechanism) speed reducer 204A (Reduction Gear) Reducer Body 204B (Upper flange of the speed reducer) 204C (lower flange of the speed reducer) 204D (Reduction Gear) Coupler 204E (Speed ​​reducer) left arm 204F (Speed ​​reducer) Right arm 204G (deceleration unit) connecting bar 205 Drilling rod (of drilling means) 206 Core tube (of drilling means) 207 (Drilling means) Support column means 207A First arm (of the support means) 207B Second arm (of the support means) 208 Water supply mechanism (of drilling means) 208A (Water supply mechanism) Water swivel 208B (Water supply mechanism) water injection ring 209 Rotation mechanism (of drilling means) 209A Support plate (for the rotating mechanism) 209B (Rotating mechanism) connecting jig 300 Testing methods (for drilling equipment) 301 Test support (of a test device) 302 Pulley beam (of the test means) 303 Pulley (of the test means) 304 (Test method) materials 305 (Testing device) Winch with pulley 306 Small engine (of test equipment) 307 Guide rod (of the test method) 308 (Testing tool) Hammer 309 (Test method) Knocking head 310 Test rod (of a test method) 311 Sampler (of a test device) 400 (base of drilling equipment) 401 (Base) Base anchor GH (support plate) guide groove GP (planetary gear of the gearbox) GR (Internal gear of the gearbox) GS (Sun gear of the gearbox) GT (Water Swivel) Water Retention Channel TH test hole WE (water inlet ring) water inlet hole WP (water swivel) water passage hole

Claims

1. A device that uses a core drill to bore holes in the ground, A drilling support column positioned vertically or approximately vertically in its axial direction, A slider is attached to the drilling support so as to move in the axial direction of the drilling support, The core drill attached to the slider, A reduction gear connected to the rotating shaft of the core drill, The rod connected to the reduction gear is provided, The reduction gear transmits rotation to the rod at a rotational speed lower than the rotational speed input from the rotating shaft of the core drill. A drilling device characterized by the following features.

2. The reduction gear is a planetary gear mechanism consisting of a sun gear, a plurality of planetary gears, a plurality of planetary carriers connected to the planetary gears, and an internal gear. The rotating shaft is connected to the sun gear either directly or indirectly via a connecting jig. The rod is connected to the planetary carrier either directly or indirectly via a connecting jig. Inside the internal gear whose rotation is restricted, a plurality of planetary gears are arranged to mesh with the internal gear and the sun gear. The planetary carrier rotates at a rotational speed less than the rotational speed of the sun gear. The drilling apparatus according to claim 1, characterized by the features described above.

3. The reduction gear is fitted with a left arm and a right arm. The left arm and the right arm grip the slider or the core drill, thereby suppressing the oscillation of the reduction body. The drilling apparatus according to feature 2.

4. A water swivel that is hollow and has water passage holes on its side, The water supply ring, which has a water supply hole on its side and is fitted onto the water swivel, further comprises The water swivel is connected to the reduction gear and also to the rod, and rotates together with a part of the reduction gear to transmit rotation to the rod. The water injection ring is fixed to a part of the reduction gear and its rotation is restricted. Water pumped through the water injection hole is supplied to the inside of the water swivel through the water passage hole. The drilling apparatus according to claim 1, characterized by the features described above.

5. The drilling support column is provided with a sliding rack arranged along the axial direction. The aforementioned slider is provided with a sliding gear, The slider moves in the axial direction of the drilling support column together with the core drill by a rack and pinion mechanism consisting of the sliding rack and the sliding gear. The drilling apparatus according to claim 1, characterized by the features described above.

6. A method of drilling into the ground using a drilling device, The drilling apparatus comprises a drilling column, a slider, a core drill, a reduction gear, and a rod. A support column installation step involves installing the drilling support column on the ground so that its axis is vertical or nearly vertical, The equipment installation process involves attaching the slider to which the core drill is attached to the drilling support column, connecting the reduction body to the rotation axis of the core drill, and connecting the rod to the reduction body. The system includes a rod rotation step in which the rod is rotated by rotating the rotating shaft with the core drill, In the rod rotation process, the rod rotates at a rotational speed lower than the rotational speed input from the rotating shaft, and with a torque greater than the torque input from the rotating shaft. As the rod rotates, a test hole is formed in the ground. A drilling method characterized by the following features.

7. In the rod rotation process, the rod, to which a core tube is connected at its lower end, is rotated, and a hole is drilled in the core tube while collecting a core sample. The drilling method according to claim 6, characterized by the features described above.

8. After drilling to a predetermined depth by the rod rotation process, the drilling device is moved to a position away from the test hole in a drilling device movement process, The system further comprises a test step, in which an in-situ test of the ground is performed after the drilling device movement step, The drilling method according to claim 6, characterized by the features described above.

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