JP2013234557A - Excavation head of excavation rod and excavating equipment for constructing hydraulic solidification material liquid substitution column - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable avoidance of continuity of construction depth at a high level and a decrease in vertical bearing capacity caused by cohesive soil remaining in a substitution column, and also improve excavatability.SOLUTION: An excavation head detachably connected to a lower end of an excavation rod 1 having a channel for a hydraulic solidification material liquid is a conical head 21 which is conically protruded downward. A peripheral surface of the conical head 21 is provided with a discharge opening 22a for the hydraulic solidification material liquid, and a spiral blade 25 is provided in the direction of pushing excavated sediment upward during the normal rotation of the excavation rod 1.

Description

  The present invention relates to a drilling head of a hydraulic solidification material liquid replacement column construction drill rod used for construction of a small-diameter pile-shaped reinforcing material by hydraulic solidification liquid replacement, and a drilling device including a drilling rod connected to the drilling head. .

  As a basic construction method for detached houses and soil slabs, a column construction method using a deep mixing method is generally adopted. This column method stirs and mixes the in-situ ground and cement slurry, so when cohesive soil with high adhesive strength is targeted, a co-rotation phenomenon occurs, resulting in poor quality due to poor mixing, organic soil, etc. Depending on the type of ground, there was a problem that solidification failure occurred. In order to solve this problem, the applicants have previously proposed a construction method for a hydraulic solidifying material liquid replacement column and a construction apparatus for a hydraulic solidifying material liquid replacement column (see Patent Document 1).

  In this prior art, as shown in FIG. 26, a drilling rod (also referred to as a drilling auger) 1 with a drilling head 8 attached to the tip is attached to an auger motor 12 capable of rotating in the forward and reverse directions. This is performed by using a construction apparatus 10 that can be fed up and down along the reader 11 (movable back and forth). A slide plate 13 is provided on the reader 11 so as to be slidable along the reader 11, and the auger motor 12 is fixed to the slide plate 13. The excavating rod 1 attached to the auger motor 12 is given a rotational force by the auger motor 12, and further advancing and retreating (sliding) the slide plate 13 along the reader 11, thereby giving a feeding force via the auger motor 12.

  27A, 27B, and 27C are examples of the excavation rod 1. FIG. The small-diameter mounting rod 1b that can be inserted into the auger motor 12 of the construction apparatus 10 is connected to the excavation rod main body 1a via an adapter 2 as shown in FIG. The excavation rod 1 is a cylindrical body having a smooth circumferential surface that is normally used over the entire length, and an excavation head 8 is detachably attached to a lower end portion of the excavation rod main body 1a. FIG. 27B shows a structure in which a comparatively short rod 1c having a small diameter having a spiral screw 3 is provided below the excavation rod body 1a. FIG. 27 (c) shows the excavation rod 1 to which the spiral screw 3 is fixed over substantially the entire length of the excavation rod main body 1a. As long as the spiral screw 3 has a soil discharging function, the spiral screw 3 is not limited to a continuous one but may be intermittent. The excavation head 8 shown in FIGS. 27A, 27B, and 27C has an excavation claw 18.

Next, a specific construction procedure for building a hydraulic solidifying material liquid replacement column in this prior art will be described with reference to FIG. This construction procedure is performed using the construction apparatus 10 shown in FIG.
(1) Pile core alignment The center of the excavation rod 1 tip attached to the auger motor 12 of the construction apparatus 10 is set according to the pile core position (FIG. 28 (a)).
(2) Excavation The excavation rod 1 is rotated while being advanced, and excavation press-fitting is performed to a predetermined depth (FIG. 28 (b)).
(3) Holding or kneading When the tip of the excavation rod 1 (excavation head) reaches a predetermined depth, the cement milk (hydraulic solidified material liquid) is discharged from the tip of the excavation head 8 of the excavation rod 1 for a certain period of time. Holding or kneading is performed (FIG. 28 (c)).
(4) Lifting The drilling rod 1 is lifted while discharging cement milk (FIG. 28 (d)).
(5) Pile head level adjustment The excavating rod 1 is pulled up, and the column top end level (pile head level) is adjusted to a predetermined position by supplementing cement milk or the like (FIG. 28 (e)). In some cases, supplementation of cement milk may be performed after completion of construction.
(6) End (FIG. 28 (f)).

Compared with the conventional ground improvement column by deep mixing treatment, the hydraulic solidification material liquid replacement column built by this prior art is not affected by the ground at all, so the high strength quality is stable. Can be obtained. Moreover, since it is not agitated and mixed with the in-situ ground, there are merits such as extremely simple construction management and quality control. Furthermore, if the cylindrical excavation rod 1 having a smooth surface as shown in FIG. 27 (a) is used, since there is no soil discharging function, it is possible to perform construction such that almost no generated residual soil is produced.
In recent years, due to the growing awareness of environmental protection, construction methods that require a small amount of residual soil during pile foundation construction have been required. Therefore, it is desirable to use the cylindrical excavation rod 1 having a smooth peripheral surface as shown in FIGS. 27 (a) and 27 (b) with the least amount of residual soil generated in this prior art. It is necessary to select the excavation rod type in consideration of the overall conditions.

  An example of the excavation head 8 connected to the tip of the excavation rod 1 is shown in FIG. The excavation head 8 connected to the tip of the excavation rod 1 in the prior art is formed by excavation claws 18 that are formed by projecting a steel plate into a square shape or a sword shape and projecting from the lower end surface. The excavation claw 18 of the excavation head 8 shown in FIG. 29A is an excavation claw having a flat bottom at the tip of the excavation rod 1, and FIG. The excavation claw 18 has a conical shape, and FIG. 29C shows the excavation claw 18 so that the bottom of the excavation rod 1 at the time of rotation is substantially flat and the column center can be easily aligned during construction. The excavation nail | claw 18 which cut | notched in the excavation rod 1 axial center position of the front-end | tip is shown.

  The excavation rod 1 is hollow, and the inside of the hollow is used as a cement milk supply passage 4 as shown in FIG. When the outer diameter of the excavation rod 1 is relatively small, the hollow inside may be used as the direct supply passage 4. However, when the outer diameter of the excavation rod 1 is relatively large, as shown in FIGS. As shown, an inner pipe 5 dedicated to the supply passage is provided. The tip of the excavating rod 1 is a discharge port 6 provided with a check valve 7, and the hydraulic solidifying material liquid (for example, cement milk) supplied through the supply passage 4 or the inner pipe 5 is And discharged from the discharge port 6.

  Further, in the construction method of the hydraulic solidifying material liquid replacement column, since the cement milk discharge port 6 is located at the lower end surface of the excavation rod 1, the weight of the cement milk is directly received. The cement milk remaining in the supply passage 4 or the inner pipe 5 of the excavation rod 1 leaks from the pipe 7 and hangs down, causing the ground surface to become dirty when the construction device 10 is moved, and the construction of the replacement column is completed. Then, when the excavation rod 1 is still on the excavation hole when the excavation rod 1 is still on the excavation hole, the excavation claw 18 of the excavation head 8 fixed at the tip of the excavation rod 1 is pulled up to the ground. There is a problem that the sediment is dropped and mixed in the replacement column that has not yet solidified, and when the cement milk is solidified without removing the excavated sediment, there is a problem that the quality of the replacement column is deteriorated. The present applicant has already proposed a drooping device for cement milk that solves this problem (see, for example, Patent Document 2).

JP 2011-106253 A Japanese Patent Application No. 2010-191723

In the excavation head 8 of the excavation rod 1 used for the construction of the above-described conventional hydraulic solidifying material liquid replacement column, as shown in FIGS. 29 (a), (b), (c), Since the digging claw 18 is processed into a sword shape, it has been found that there are the following problems.
(1) When construction is performed using the excavation rod 1 having no soil removal mechanism as shown in FIG. 27A, when the excavation target ground J is sandy soil as shown in FIG. If the pushing force in the direction of the arrow S is applied in a state where the excavated earth and sand cannot be removed upward, the shear resistance force of the excavated earth and sand in the direction of the arrow R increases. May fall or become unable to dig. If it falls into such a situation, construction cannot be carried out to a predetermined depth, resulting in a construction trouble of so-called high stopping.

(2) When there is a viscous soil (layer) during the construction depth in the ground J of the hydraulic solidifying material liquid replacement column, the viscous soil adheres to the excavation claw 18 and moves in the direction of arrow T shown in FIG. 31 (a). When the excavating rod 1 is pulled up, the viscous soil D adhering to the tip is pulled up together with the excavating claw 18 in the replaced hydraulic solidifying material liquid M. However, when impact, vibration, or the like is applied to the excavation rod 1 from the construction device 10, the attached viscous soil D peels from the excavation claw 18, falls into the hydraulic solidifying material liquid M, and is shown in FIG. 31 (b). As shown, it may remain in the hydraulic solidifying material liquid M to be a replacement column. When the viscous soil mass D remains in the replacement column in this way, it is considered that the vertical supporting force of the replacement column is reduced. FIG. 32 shows the result of the indentation loading test in which the viscous soil mass D corresponding to the rotating volume of the excavation claw 18 was intentionally deposited on the bottom of the replacement column and the other was not built. The specifications of the replacement column are a design outer diameter of 200 mm and a length of 6 m. When the pile head settlement amount reaches 20 mm, the loading load (second limit resistance) is 193 kN without the viscous soil mass D, becomes 126 kN with the viscous soil mass D, and the second when the viscous soil mass D exists at the bottom. The limit resistance decreased to about two-thirds.

The present invention provides an excavation head for a hydraulic solidification material liquid displacement column construction drill rod that solves the problems of the conventional high depth of construction and the decrease in vertical bearing force due to the accumulation of viscous soil on the bottom of the displacement column, and A first object is to provide a drilling device including a drilling rod provided with the drilling head.
Further, the present invention provides a drilling head for a hydraulic solidifying material liquid replacement column construction drill that enables dripping of the hydraulic solidifying material liquid leaking from the lower end of the drilling rod, and a drilling device including the drilling rod provided with the drilling head. The purpose of 2.

The present invention has been made to eliminate the above-mentioned drawbacks of the prior art, and the invention of claim 1 is a drilling head of a drill rod for building a hydraulic solidifying material liquid replacement column, comprising a hydraulic solidifying material. A conical head provided in a lower end portion of the excavation rod having a liquid flow path and projecting downward in a conical shape, and the circumferential surface of the conical head discharges hydraulic solidifying material liquid that leads to the flow path. The present invention provides a drilling head for a drill rod for building a hydraulic solidifying material liquid replacement column, characterized in that a spiral blade is provided in a direction in which an outlet is provided and a drilling soil is pushed upward during forward rotation of the drilling rod.
According to a second aspect of the present invention, in the first aspect, the excavation head of the excavation rod for building a hydraulic solidifying material liquid replacement column according to the first aspect, wherein the maximum outer diameter of the excavation head during rotation does not exceed the rotation diameter of the excavation rod. Is to provide.
The invention according to claim 3 is the hydraulic solidifying material liquid replacement column according to claim 1 or 2, wherein a built-up portion formed by welding is formed on an upper peripheral surface of the conical head. A drilling head for a construction drilling rod is provided.
According to a fourth aspect of the present invention, there is provided the hydraulic solidifying material liquid replacement according to any one of the first to third aspects, wherein the outer diameter of the upper end portion of the conical head is substantially the same as the outer diameter of the excavating rod. The drilling head of the drill rod for column construction is provided.
A fifth aspect of the present invention relates to any one of the first to fourth aspects,
The spiral blade provided on the peripheral surface of the conical head is provided in a region that does not reach the position of the upper end of the conical head. To do.
A sixth aspect of the present invention is the hydraulic solidification according to the fifth aspect, wherein the circumferential surface from the upper end position of the conical head to the upper end of the spiral blade is a built-up portion built up by welding. An excavation head for an excavation rod for constructing a material / liquid replacement column is provided.
According to a seventh aspect of the present invention, there is provided a drill rod for building a hydraulic solidifying material liquid replacement column according to any one of the first to sixth aspects, wherein the drill rod and the conical head are connected by welding. A drilling head is provided.
The invention according to claim 8 is the hydraulic solidification material liquid replacement column construction according to any one of claims 1 to 7, wherein a check valve is provided at a discharge port of the hydraulic solidification material liquid. An excavation head for an excavation rod is provided.
According to a ninth aspect of the present invention, in any one of the first to eighth aspects, the hydraulic solidifying material liquid discharge port has a conical head cut off from a central position thereof at a rear side in a rotation direction during excavation rotation of the excavation rod. An excavation head for an excavation rod for building a hydraulic solidifying material liquid displacement column, characterized in that it is processed to a height lower than the conical surface of the present invention.
A tenth aspect of the present invention is the hydraulic solidification according to any one of the first to ninth aspects, further comprising a protrusion or a hole for hanging the hydraulic solidifying material liquid receiver at the forefront of the conical head. An excavation head for an excavation rod for constructing a material / liquid replacement column is provided.

According to an eleventh aspect of the present invention, there is provided a drilling apparatus for building a hydraulic solidifying material liquid replacement column, wherein the drilling head according to any one of the first to tenth aspects is connected to a lower end portion of a drilling rod. Is to provide. The term “connection” here includes both detachable and fixed.
According to a twelfth aspect of the present invention, the excavation rod is an unequal thickness pipe having a large wall thickness within a range of at least 0.5 m from the lower end. Provided is a drilling device for building a hydraulic solidifying material liquid displacement column comprising a drilling rod having a drilling head to be described.
According to a thirteenth aspect of the present invention, the wear portion of the lower peripheral surface of the excavation rod is formed in a built-up portion that is built up by welding, and the lower end portion of the excavation rod has any one of the first to tenth aspects. A drilling apparatus for building a hydraulic solidifying material liquid replacement column, comprising a drilling rod having the drilling head described in the above section.

The invention according to claim 14 is the lower part of the excavation rod body having a smooth peripheral surface without a soil removal mechanism, the outer diameter of which is the same as or slightly smaller than the excavation rod body, and the excavation soil is moved upward during normal rotation. A relatively short spiral rod having a spiral screw in a pushing direction is connected, and a drilling rod provided with the drilling head according to any one of claims 1 to 10 is provided at a lower end of the spiral rod. An excavating apparatus for building a hydraulic solidifying material liquid replacement column is provided.
A fifteenth aspect of the present invention provides a drilling apparatus for building a hydraulic solidifying material liquid replacement column according to the fourteenth aspect, wherein the length of the spiral rod does not exceed 2 m at most.
According to a sixteenth aspect of the present invention, in the lower end of the excavation rod body provided with a spiral screw in a direction for pushing up the excavated earth and sand during normal rotation over the substantially entire length of the peripheral surface, A drilling device for building a hydraulic solidifying material liquid replacement column, comprising a drilling rod provided with the drilling head described in the above section.

If the hydraulic solidification material liquid replacement column is constructed by the excavation head having the excavation head of the hydraulic solidification material liquid replacement column construction drill according to the present invention and the excavation rod provided with the excavation head, the following effects can be obtained. .
(1) According to the excavation head of the excavation rod for constructing the hydraulic solidifying material liquid replacement column according to the first aspect of the present invention, the head main body is a conical head projecting downward in a conical shape, and the peripheral surface of the conical head Since the spiral wing is projected, the excavated sediment at the tip of the head is excavated by the spiral wing and smoothly pushed upward along the spiral wing at the time of excavation. For this reason, even if the ground excavated soil is sandy soil, good excavation performance can be secured by the synergistic effect of the conical shape of the conical head and the spiral blade. Therefore, even if the excavation rod is an excavation rod having a smooth peripheral surface without any soil removal mechanism, relatively good excavation performance is exhibited. If one having a spiral screw protruding on the peripheral surface of the excavation rod itself is used, the excavation performance is further improved.

(2) Since the main part of the excavation head is a conical head, the viscous soil that adheres to the excavation head during the excavation of the viscous ground is only the relatively thin rotor part formed by the spiral blade. For this reason, unlike a conventional excavation head that uses excavation claws (steel plate claws), it does not structurally form a clot. In addition, even if a clot with the same thickness as the height of the spiral blade is attached, the spiral blade supports this from below, so that the attached clot will peel off from the excavation head due to the adhesive force of the viscous soil. There are few. As a result, it is possible to solve the problem that the digging performance remains high in the sand ground, and to avoid the lack of support force of the replacement column based on the fall of the soil mass in the hydraulic solidifying material liquid during the digging.

(3) According to the excavation head of the hydraulic solidifying material liquid replacement column construction drilling rod according to the invention of claim 2, the hole wall that defines the outer diameter of the replacement column is formed by the rotational sliding effect of the outer diameter of the drilling rod. Is done. If the maximum outer diameter during rotation of the excavation head exceeds the rotation diameter of the excavation rod, the excavation head is at the lowermost end of the excavation rod, and therefore the hole wall formed in the excavation rod lifting process is scraped off. In this case, the scraped hole wall soil remains in the replaced hydraulic solidifying material liquid. Therefore, after hardening of the hydraulic solidifying material liquid, a small earth lump that is shavings is contained, and if the amount exceeds the allowable value, the quality of the replacement column becomes poor. According to the invention of claim 2, there is an effect that such a quality defect is not caused.

Using a drilling rod fitted with a conical head with spiral wings as a drilling head and repeatedly building a hydraulic solidification liquid replacement column in sandy ground, the drilling head and drilling rod are sandy. Wear due to excavation resistance of the ground. For example,
a. By repeating the construction in the sandy ground, the portion of the lower end surface of the excavation rod that protrudes from the upper end portion of the conical head is worn violently and tends to approach the ridgeline of the conical head.
b. Since the excavated earth and sand is guided relatively upward along the spiral blade of the conical head, the peripheral surface near the upper end of the spiral blade of the conical head becomes a passage for the guided and moved earth and sand, and this portion is Abrasion due to moving earth and sand.
c. Wear in the section of 0.5 to 1 m from the lower end of the lower peripheral surface of the excavation rod is severe.
When such wear progresses, the conical head and the excavation rod may be damaged, and the construction of the hydraulic solidifying material liquid replacement column itself may become impossible.
(4) According to the excavation head of the excavation rod for building a hydraulic solidifying material liquid replacement column according to the inventions of claims 3 to 6, the progress of such wear can be delayed and the life of the conical head and the excavation rod can be extended. it can.

(5) According to the excavation head of the excavation rod for building the hydraulic solidifying material liquid replacement column according to the inventions of claims 3 and 6, the region from the upper peripheral surface of the conical head or the upper end position of the conical head to the upper end of the spiral blade However, wear is most likely to proceed in this region (part) because it receives the greatest excavation resistance from sandy ground or the like. However, by providing a weld overlay in this wear region in advance, the life is extended and this wear proceeds. By applying welding to the worn area, the conical head can be reused, and as a result, the life of the conical head can be extended.

(6) According to the excavation head of the hydraulic solidification material liquid replacement column construction excavation rod according to the invention of claim 7, the excavation rod and the conical head are connected to each other by welding (for example, groove welding). In other words, the excavation rod and the conical head can be quickly and easily maintained with sufficient strength by being welded to a concave groove such as a V shape or U shape formed between them. Can be connected.

(7) According to the excavation head of the hydraulic solidification material liquid replacement column construction drill rod according to the invention of claim 8, if the excavation earth and sand flows backward from the discharge port during excavation, the hydraulic solidification material liquid may not be discharged. Therefore, the installation of a check valve prevents it. Since the check valve itself is subjected to ground resistance during excavation work, it must be rigid and durable enough to withstand it. The spring force prevents leakage of hydraulic solidified liquid and opens when the discharge pressure is applied to solidify hydraulically. Discharge the material liquid. Also, a check valve using an elastic rubber plate or an elastic resin plate can be used. In either example, the check valve is attached by countersinking the peripheral surface of the conical head. This is a contrivance to prevent ground resistance during rotation during excavation from acting directly on the check valve, which improves the durability of the check valve. Further, it is preferable that the inner diameters of the flow paths are substantially the same because clogging of the hydraulic solidifying material liquid is less likely to occur.

(8) According to the excavation head of the excavating rod for constructing the hydraulic solidifying material liquid replacement column according to the invention of claim 9, the excavated earth and sand are discharged by the action of the edge of the discharge account turning portion when the excavating rod is rotated. It collects on the check valve at the outlet, prevents the check valve from opening, and prevents a phenomenon that makes it difficult to discharge the hydraulic solidifying material liquid. The excavation rod at the time of excavation rotates in a direction in which spiral wings protruding from the circumferential surface of the conical head move the excavated soil upward. If it does so, since the countersink part edge behind the said rotation direction from the center position of a discharge port will carry out the effect | action which scrapes the ground, cutting soil accumulates on the check valve which faces a countersink part. When the cut sediment accumulated in this way fills the countersink portion by the excavating action and it is compacted, the check valve does not open and close, and the hydraulic solidifying material liquid cannot be discharged and the construction cannot be performed. Therefore, the occurrence of the above-described trouble can be prevented by scraping off the countersink part edge behind the center position of the countersink part around the discharge port so as not to cause the ground cutting action by the edge. Any other cutting shape can be arbitrarily adopted as long as it reduces the ground cutting action of the edge.

(9) According to the excavation head of the excavation rod for building the hydraulic solidification material liquid replacement column according to the invention of claim 10, the hydraulic solidification material liquid is discharged from the discharge port while the construction device of the hydraulic solidification liquid replacement column is moving. In order to prevent the ground from leaking and soiling the ground, a projection or insertion hole for suspending a bucket, a pan, or the like is provided at the lower end of the excavation head where the check valve faces. The insertion hole has a direct insertion hole in the conical part of the conical head, a steel plate that also functions as a conical head excavation claw, and a steel plate that also functions as an excavation claw. The hole is formed with a steel rod. The method of use at the time of construction is to suspend the bucket or pan etc. at the lower end of the excavation head by suspending the hook that holds the bucket or bread hanging string from the projection or passing it through one of the insertion holes. Can be hung. Thereby, it is possible to avoid the hydraulic solidifying material liquid leaking from the discharge port during the movement of the construction apparatus being collected in the bucket, the bread, or the like and soiling the construction site. In addition, all the said insertion holes should just be a shape and size which can suspend a bucket, a bread | pan, etc.
Further, a protrusion is provided at the tip of the conical head, and a disk having a diameter larger than the shaft diameter of the protrusion main body is fixed to the tip of the protrusion. The projection may be provided at a symmetrical position with respect to the excavation head at the tip of the cone. Furthermore, a hook-shaped protrusion may be provided at the tip of the conical portion. In addition, the said protrusion should just be a shape which can suspend a bucket, a bread | pan, etc. similarly to the said insertion hole.

(10) According to the excavating apparatus for building a hydraulic solidifying material liquid replacement column according to the invention of claim 11, since the excavating rod has a conical head provided with a spiral blade at the tip, the excavating rod has good excavation performance and is sandy. Digging work is possible even on soil. In addition, the connection method of a conical head and an excavation rod may be detachable or fixed by welding.
(11) According to the excavator for building a hydraulic solidifying material liquid replacement column according to the invention of claim 12, in addition to the effects of claims 1 to 9, a thickness of at least 0.5 m from the lower end of the excavation rod is thick. Since the unequal-thickness tube has a large thickness, the portion where the rod is heavily worn is thick, so the life can be extended.

(12) According to the excavator for building a hydraulic solidifying material liquid replacement column according to the invention of claim 13, in addition to the effects of claims 1 to 11, the worn portion of the lower peripheral surface where the wear of the excavating rod is severe. Since it is formed in the built-up part that is built up by welding, the life is extended, and even if the wear progresses, it is possible to reuse it by providing the built-up by welding in this wear area, and improve the economic efficiency. Can be achieved.

(13) According to the excavating apparatus for building a hydraulic solidifying material liquid replacement column according to the invention of claim 14, in addition to the effects of the first to thirteenth aspects, the amount of excavated soil can be suppressed little or little. In addition, the excavation performance is improved and the construction time can be shortened.

(14) Further, in claim 15, by setting the length of the spiral rod to 2 m or less, the balance with the excavation rod is good, the amount of soil removal is not generated or reduced, and the effect of kneading the hole wall is improved. it can.

(15) According to the excavator for building a hydraulic solidifying material liquid replacement column according to the invention of claim 16, in addition to the effects of claims 1 to 13, the excavation performance is high, the construction time is the shortest, and the construction efficiency is improved. Can be planned. However, as compared with the invention of the fourteenth aspect, there is a difficulty in causing soil discharge.

  The present invention has been briefly described above. Further, the best mode for carrying out the present invention will be described below in detail with reference to the accompanying drawings.

The principal part of the excavation head of the excavation rod for hydraulic solidification material liquid substitution column construction by an embodiment of the present invention is shown, (a) is a front view and (b) is a back view. It is sectional drawing of the excavation head of the excavation rod for hydraulic solidification material liquid substitution column construction shown in FIG. It is sectional drawing which shows the other excavation head of the excavation rod for hydraulic solidification material liquid substitution column construction in FIG. It is a front view of the conical head which shows another example. It is the sectional view on the AA line of the conical head in FIG. It is a BB line sectional view of the conical head in Drawing 1 (a). It is a front view which shows the other form of the conical head in FIG. It is a front view which shows the other form of the conical head in FIG. It is a front view which shows the other form of the conical head in FIG. It is a front view which shows the suspended state of a hydraulic solidification material liquid holder. It is a front view which shows the other form of the conical head in FIG. It is a front view which shows the other form of the conical head in FIG. It is a front view which shows the other form of the conical head in FIG. It is explanatory drawing (a) (b) for demonstrating the excavation performance by the difference in the cone angle of a cone head. It is a front view (a) (b) (c) which shows the excavation rod with which the excavation equipment of the present invention is provided. It is a front view which shows the excavation rod with which the excavation apparatus of a comparative example is provided. It is the soil columnar figure (a) of the ground which implemented the construction test, and a Swedish sounding test result (b). It is a figure which shows the relationship between the excavation depth and excavation time of each Example and a comparative example. It is sectional drawing which shows the other form of a conical head, and shows the fixed connection structure of a drilling rod and a conical head. It is a front view which shows the other form of a cone head, and shows the case where a build-up part is given to the upper peripheral surface of a cone head. It is a front view which shows the other form of a cone head, and shows the case where a spiral blade is provided in the area | region which does not reach the upper end part position of a cone head. It is a front view which shows the other form of a cone head, and shows the case where a build-up part is given to the area | region from the upper end part position of a cone head to the upper end of a spiral blade. It is a front view which shows other embodiment of this invention, and shows the case where a build-up part is given to the abrasion area | region of the excavation rod lower peripheral surface. It is a front view which shows other embodiment of this invention, and shows the case where a built-up part is given to the wear area | region from the upper end part position of a cone head to the upper end of a spiral blade, and the wear area | region of a drilling rod lower peripheral surface. It is a principal part front view explaining the wear condition of a cone head and a drilling rod, (a) shows before wear, (b) shows after wear. It is a front view which shows the conventional general construction apparatus. It is a front view which illustrates the conventional excavation rod (a) (b) (c). It is explanatory drawing which shows the construction procedure of hydraulic solidification material liquid substitution column construction in process order (a) (b) (c) (d) (e) (f). It is a perspective view (a) (b) (c) of the principal part showing the excavation head of the conventional excavation rod tip. It is explanatory drawing which shows the excavation state of the excavation head with respect to sandy soil. It is explanatory drawing (a) (b) which shows the action state of the excavation head with respect to cohesive soil. It is a graph which shows the loading test result performed about what deposited the viscous earth lump equivalent to the rotation volume of an excavation head, and the thing which is not deposited on the bottom of a substitution column.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 25.

  1 and 2 show a drill head of a drill rod for building a hydraulic solidifying material liquid replacement column according to the present embodiment. The excavation head of the excavation rod for building the hydraulic solidifying material liquid replacement column is formed by connecting a conical head 21 to the end of the excavation rod body 1a of the excavation rod 1 that is substantially the same as that shown in FIG. Specifically, the conical head 21 has a hydraulic solidifying material liquid flow path 22 detachably or fixedly connected to the lower end of the excavating rod 1 and protrudes downward from the conical part 21b. The hydraulic solidification material liquid discharge port 22a is provided on the peripheral surface of the drill rod, and the spiral blade 25 pushes up the excavated earth and sand when the excavation rod 1 rotates forward (during excavation rotation).

  In this configuration, during excavation work, the excavated sediment at the tip of the conical head 21 is excavated by the spiral blade 25 and is smoothly pushed upward along the spiral blade 25, so that the conical head is against the sandy excavated sediment. 21 good excavation performance can be secured. Therefore, even if the excavation rod 1 is the excavation rod 1 having a smooth peripheral surface without any soil removal mechanism, it exhibits a relatively good excavation performance. And if the thing which protruded the spiral screw 3 as shown in FIG.15 (b) (c) to the surrounding surface of the excavation rod 1 itself as mentioned above is used, excavation property will improve further.

  The main part of the conical head 21 is conical. For this reason, the viscous soil that adheres to the conical head 21 during the excavation of the viscous ground is only the spiral blade 25 portion. Therefore, unlike the conventional excavation head that uses the excavation claw of the steel plate, Absent. Further, even if an adhered soil layer having a thickness substantially the same as the height of the spiral blade 25 is formed, the spiral blade 25 supports this from the lower side, and therefore, in combination with the adhesive force of the viscous soil, Does not peel off from the excavation head 21. As a result, it is possible to eliminate the high digging trouble in the sandy ground and to avoid the lack of support capacity of the replacement column due to the fall of the soil mass into the hydraulic solidification material liquid, and to work on the excavated soil Column deterioration due to soil contamination and dirt mixing can be avoided.

The conical head 21 is formed by integrating the base portion 21a and the conical portion 21b by welding, for example, and can be obtained as an integrally molded product (for example, a cast product) as necessary. The base portion 21a is detachably attached to the end of the cylindrical excavation rod 1 for maintenance, inspection, etc. or for parts replacement, for example. As shown, fasteners P such as pins are used at a plurality of locations. In this example, a joint 40 is fixed to the lower end of the excavation rod 1 (excavation rod body 1a), and the conical head 21 is detachably attached to the joint 40 with a fastener P (see FIGS. 2 and 3). ).
Although the conical head 21 is detachably attached to the end of the excavation rod 1 here, the conical head 21 may be fixed (for example, welded) to the end of the excavation rod 1.

  Further, the conical head 21 has a flow path (communication hole) 22 that is continuous with the entire length of the base portion 21a and a part of the conical portion 21b at the center thereof. The lower end of the channel 22 faces the outer peripheral surface of the conical portion 21b, and the opening end serves as a hydraulic solidifying material liquid discharge port 22a described later. The discharge port 22a is provided with a check valve 23 having a spring structure. When the hydraulic solidifying material liquid is fed to the flow path 22, the pressure is automatically received against the spring force. be opened. On the other hand, when the pumping of the hydraulic solidifying material liquid stops, the check valve 23 automatically closes the discharge port 22a by the spring force to prevent the earth and sand in the ground from flowing back to the flow path 22. If the excavated earth and sand flows backward from the discharge port 22a during excavation, the hydraulic solidifying material liquid may not be discharged, so the check valve 23 is prevented from being installed. Since the check valve 23 itself is subjected to ground resistance during excavation work, it must be rigid and durable enough to withstand it. The spring force prevents leakage of the hydraulic solidified liquid and opens when the discharge pressure acts. Discharge the solidified material liquid.

  Instead of the check valve 23 having the spring structure, as shown in FIG. 3, a check valve 24 made of elastic rubber or elastic resin partially fixed to the discharge port 22a may be used. In any of the check valves 23 and 24, the check valve 23 and 24 are attached by countersinking the circumferential surface of the conical portion. This is a device for preventing the ground resistance during rotation during excavation from directly acting on the check valves 23 and 24, thereby improving the durability of the check valves 23 and 24. Further, the flow path (communication path) 22 in the conical head 21 changes its direction near the discharge port. It is preferable that the inner diameters of the flow paths be approximately the same because clogging of the hydraulic solidifying material liquid is less likely to occur. Since the check valve 24 has a simple configuration and can be easily attached with an elastic rubber material or an elastic resin material, the replacement work for the conical head 21 is easier than the check valve 23 with a spring structure, and the cost can be greatly reduced. High practicality.

  Further, a supply pipe 5 (inner pipe) for supplying a hydraulic solidifying material liquid from the outside of the excavation rod 1 is connected to the upper end of the flow path 22. It is optional to omit the supply pipe 5 and guide the hydraulic solidified material liquid to the flow path 22 of the conical head 21 through the hollow portion of the excavation rod 1. Further, the conical head 21 has one spiral blade 25 of a predetermined height protruding from the outer periphery. Two or more spiral blades 25 may be optionally provided or intermittently. Even if the excavation rod 1 does not have a soil discharging function as shown in FIG. 15A, the spiral blade 25 scoops up the earth and sand along the conical surface during excavation by the rotation of the conical head 21. Since the excavated soil is pushed to the side by the peripheral surface of the raised excavating rod 1, even if the excavated soil is sandy soil, the phenomenon shown in FIG. 30 does not occur. Thereby, even if earth and sand are sandy soil, it can be propelled into the ground without a large (excessive) resistance.

  When the earth and sand are viscous soil, when the ground is excavated by the promotion of the conical head 21, when it is pulled up to the ground, the viscous soil is formed on the outer peripheral surface of the conical head 21 between the spiral blades 25 facing vertically. Adhere to. Since this viscous soil is supported by the spiral blade 25, coupled with the adhesive force of the viscous soil, it hardly peels off from the outer peripheral surface of the conical head 21 and falls and remains in the constructed column. As a result, it is possible to avoid the deterioration of the vertical supporting force of the column accompanying the mixing of earth and sand.

  By the way, it is important that the maximum outer diameter at the time of rotation of the conical head 21 does not exceed the rotation diameter of the excavation rod 1. The hole wall that defines the outer diameter of the column that is the replacement column body is formed by the rotational sliding effect of the outer diameter of the excavating rod 1. When the maximum outer diameter of the conical head 21 during rotation exceeds the rotational diameter of the excavating rod 1, the conical head 21 is at the lowermost end of the excavating rod 1, so that the hole wall formed in the lifting process of the excavating rod 1 is scraped off. Become. For this reason, the scraped hole wall soil will remain in the replaced hydraulic solidifying material liquid, and after the hardening of the hydraulic solidifying material liquid, a small soil mass that is shavings will be included in the column, If the amount exceeds the allowable value, the quality of the hydraulic solidifying material liquid replacement column will be poor. For this reason, the maximum outer diameter at the time of rotation of the conical head 21 is made not to exceed the rotation diameter of the excavation rod 1. Further, as shown in FIGS. 19 and 21 described later, even when the conical head 21 is fixed to the lower end of the excavation rod 1 by welding or the like, the outer diameter of the upper end portion 21c of the conical head 21 is substantially equal to the outer diameter of the excavation rod 1. By making it the same, it is possible to prevent the hole wall from being scraped off, so that the wall soil can be prevented from remaining in the hydraulic solidifying material liquid.

  As shown in FIGS. 4 and 5, the discharge port 22a of the flow path 22 is flatly cut from the center position at the rear side in the rotation direction of the excavating rod 1 during normal rotation (spotted), and has a conical shape. The counterbore 26 is lower (smaller in diameter) than the outer peripheral surface of the head 21. As shown in FIG. 1A and FIG. 6, the sharpened edge E facing the rear side in the rotation direction of the excavation rod 1 in the counterbore 26 formed around the discharge port 22 a is the ground by the excavation head 21. During the excavation, the hole wall was shaved to accumulate the earth and sand G on the check valve 24, and the check valve 24 could be prevented from opening and closing, thereby making it impossible to discharge the hydraulic solidifying material liquid. The formation of the counterbore 26 of the present embodiment suppresses the cutting of the hole wall during ground excavation, prevents sediment from accumulating on the check valve 24, opens / closes the check valve 24, and The discharge of the hard solid material liquid can be facilitated.

  As shown in FIG. 5, the counterbore part 26 of the present embodiment is provided with one flat surface 26 a parallel to the center line of the excavation rod 1 on the side where the discharge port 22 a is provided, and substantially orthogonal to the flat surface 26 a. And a vertical surface 26b. The vertical surface 26b is located on the front side in the rotational direction of the excavating rod 1. On the other hand, the flat surface 26a is on the opposite side of the vertical surface 26b to the front side in the rotational direction, and is located at a position that falls inward from the outer peripheral surface (arc surface) of the conical head 21 and intersects the arc surface. However, the counterbore 26 occupies a large area. Therefore, this intersection becomes an obtuse edge F. As a result, when the excavation rod 1 is rotated, it is possible to prevent the end portion (obtuse edge F) on the rear side in the rotation direction of the counterbore portion 26 from cutting the hole wall of the ground during excavation. Thereby, it is possible to avoid obstructing the opening / closing operation of the check valve 24 and the discharge of the hydraulic solidifying material liquid.

  Further, the lower end (tip) of the conical head 21 of the excavation rod 1 is a hydraulic solidification material that receives the hydraulic solidification material liquid that leaks from the discharge port 22a via the check valve 24 after the excavation rod 1 is pulled up to the ground. A suspension hole for the liquid receiver is provided. As the suspension hole of the hydraulic solidifying material liquid receiver, as shown in FIG. 7, an insertion hole (hole) 27 drilled at the lower end of the conical portion of the conical head 21 and as shown in FIG. An insertion hole (hole) 29 drilled in a rectangular steel plate 28 that also functions as a drilling claw, and a steel rod 30 attached by welding or the like to the lower end of the conical portion of the conical head 21 as shown in FIGS. An insertion hole (hole) 31 is used which is made by bending the wire into an arc shape.

  These insertion holes (holes) 27, 29, 31 are hydraulic solidifying material liquid receivers through a steel hook 34 that holds a suspension string 33 of a suspension bucket 32, for example, as shown in FIG. 10. A bucket 32 or a pan is suspended from the lower end of the excavation head 1. Thereby, it is possible to prevent the hydraulic curable material liquid leaking from the discharge port 22a during the movement of the construction machine from being collected in the bucket, the pan, etc., and contaminating the construction site. Each of the insertion holes 27, 29, and 31 has a shape and size that can suspend a bucket 32, a pan, or the like.

  Furthermore, it is also possible to employ a configuration in which a protrusion is provided at the lower end of the conical head 21 and a bucket, a pan, or the like that receives the hydraulic solidifying material liquid leaking from the discharge port 22a is suspended from this protrusion. FIG. 11 shows a conical head 21 having a protrusion 35 having a large-diameter portion 35a for retaining it horizontally fixed to the lower end of the conical head 21. As shown in FIG. FIG. 12 shows a steel plate 36 that also serves as an excavation claw projecting from the lower end of the conical head 21, and projections 37 having large-diameter portions 37 a for preventing slippage are fixed horizontally on both surfaces of the steel plate 36. Further, FIG. 13 shows a conical head 21 provided with a hook-shaped protrusion 38 formed by bending a steel rod at the lower end.

  These protrusions 35, 37, and 38 lock the hook 32 that holds the suspension string 33 of the suspension bucket 32 that is a hydraulic solidifying material liquid receiver, so that the bucket 32 is attached to the lower end of the conical head 21. Can be suspended easily and quickly. Also in this case, the hydraulic curable material liquid that leaks from the discharge port 22a during the movement of the construction machine can be collected in this bucket, bread, etc., thereby avoiding soiling the construction site. The protrusions 35, 37, and 38 are all shaped and sized to be able to lock the hook 34.

  In addition, the digging ability by the difference in the cone angle of the cone head 21 was compared. 14A shows the conical head 21 having a cone angle of about 32 °, and FIG. 14B shows the conical head 21 having a cone angle of about 48 °. In terms of digging ability, a smaller cone angle is superior to a larger cone angle. On the other hand, regarding the manufacturing cost, if the method is to manufacture by cutting the conical part out of round steel, the one with the larger cone angle is cheaper. If emphasis is placed on excavation workability, it is necessary to reduce the cost by, for example, making the conical portion a cast steel. During construction, if the cone angle exceeds 45 °, the digging ability decreases, while if the cone angle is less than 30 °, the production cost may increase or the tip may become narrow, which may cause durability problems. There is. Therefore, the cone angle is preferably about 30 ° to 40 °.

  As described above, in the present embodiment, the conical head 21 protruding conically downward is detachably or fixedly connected to the lower end portion of the excavating rod 1 having the flow path of the hydraulic solidifying material liquid, The hydraulic solidifying material liquid discharge port 22a is provided on the peripheral surface of the conical head 21, and the spiral blade 25 is provided in the direction of pushing the excavated soil upward when the excavating rod 1 rotates forward. Since it is excavated by the spiral blade 25 and pushed up smoothly along the spiral blade 25, good excavation performance can be ensured even if the excavated soil is sandy soil. Therefore, even if the excavation rod 1 is the excavation rod 1 having no soil removal mechanism and a smooth peripheral surface, relatively good excavation performance is exhibited. If one having a spiral screw projecting from the peripheral surface of the excavation rod 1 itself is used, the excavation performance is further improved.

  In addition, the tip (lower end) of the conical head 21 is provided with projections 35, 37, 38 or insertion holes 27, 29, 31 for suspending the hydraulic solidifying material liquid receiver, and the projections 35, 37, 38 or insertion. The hydraulic solidifying material is suspended from the discharge port 22a while the construction apparatus is moving by suspending the bucket 32 or the pan hook 34, which is the hydraulic solidifying material liquid receiver, in the holes 27, 29, 31. It is possible to prevent the liquid from leaking and falling to the ground and soiling the surroundings, and to prevent the vertical support force from being lowered due to the high depth of construction and the remaining of clay soil in the replacement column.

  FIGS. 15A, 15B, and 15C are front views showing the excavation rod 1 to which the conical head 21 as described above is connected as the excavation head. The excavation rod 1 shown in FIG. 15A is attached to an upper portion of an excavation rod main body 1 a having a cylindrical shape and a flat (smooth) side surface (circumferential surface) via an adapter 2. The conical head 21 is connected to the lower end of the excavation rod body 1a as an excavation head. For example, the conical head 21 is connected to the excavation rod main body 1a via the joint 40 as shown in FIGS. The maximum outer diameter during rotation of the conical head 21 and the outer diameter of the joint 40 are equal to or less than the outer diameter of the excavation rod body 1a. The excavation rod 1 has a cylindrical excavation rod body 1a and has a flat side surface (smooth), and since there is no soil removal mechanism even when rotated, the excavation sediment cannot be excavated and moved sideways. It only has a function.

  The excavation rod 1 shown in FIG. 15 (b) has an outer diameter slightly smaller than that of the excavation rod main body 1a at the lower portion of the excavation rod main body 1a having a flat (smooth) side surface (circumferential surface) without a soil removal mechanism. A relatively short spiral rod 1c having a small diameter and having a spiral screw 3 that pushes up excavated earth and sand during forward rotation is connected, and a conical head 21 as an excavating head is attached to and detached from the lower end of the spiral rod 1c. It is connected freely. The spiral rod 1c is detachably connected to the excavation rod body 1a via a joint. Since the spiral rod 1c is relatively short, the spiral rod 1c may be integrally coupled with the conical head 21 or the excavation rod body 1a so as not to be detachable. The excavation rod main body 1a shown in FIG. 15 (b) is also cylindrical and has a flat side surface, and since there is no earth removal mechanism even when rotated, the excavation sediment cannot be excavated and has a function of moving to the side. It has only. Moreover, it is arbitrary to connect the spiral rod 1c and the conical head 21 integrally.

  The excavation rod 1 shown in FIG. 15 (c) has a conical head as an excavation head at the lower end of the excavation rod main body 1a provided with a spiral screw 3 in a direction to push up excavation earth and sand during normal rotation over substantially the entire length of the side surface. 21 is connected. This excavation rod 1 has a soil discharging function because the spiral screw 3 is provided over substantially the entire length of the excavation rod main body 1a.

Next, using the excavator provided with the excavation rod 1 shown in FIGS. 15 (a) and 15 (b), the ground shown in FIG. 17 (a) is excavated to GL-8m, and the excavation performance is evaluated from the excavation state. A construction test was conducted. In this excavation, no hydraulic solidifying liquid or fresh water was used.
In this construction test, the excavator provided with the excavating rod 1 shown in FIG. 15A was used as Example 1, and the excavator provided with the excavating rod 1 shown in FIG. The length of the spiral rod 1c of the excavation rod 1 in Example 2 of this example was 1 m. In FIG. 15 (b), the excavation rod main body 1a, the 1m spiral rod 1c, and the conical head 21 are detachably connected via joints. 1c may be fixed and only the conical head 21 may be detachably connected via a joint, or the spiral rod 1c and the conical head 21 may be fixed and detachable from the excavation rod main body 1a via a joint. You may connect to. As a result, the number of joint parts having a high manufacturing cost can be reduced, so that the manufacturing cost of the excavator can be reduced. Moreover, the excavator provided with the excavation rod 1 shown in FIG. 16 was used as a comparative example. The excavation rod 1 shown in FIG. 16 is shown in a conventional example, and an excavation rod main body 1a having an attachment rod 1b connected to the upper side via an adapter 2 has a side surface (circumferential surface) over its entire length. Is a smooth cylindrical body, and the excavation head 8 is attached to the lower end of the excavation rod main body 1 a, and the excavation head 8 includes excavation claws 18.

FIG. 17A shows the soil columnar diagram of the ground subjected to the construction test and the N value by the standard penetration test, and FIG. 17B shows the Swedish sounding test result.
According to the soil columnar diagram of FIG. 17 (a), the ground subjected to the construction test has a loam layer having an N value of 4 up to GL-1.95m below the 0.3m topsoil by embankment, and N below A tuff clay layer with a value of 1 is deposited, followed by a loose fine sand layer below it. From GL-5m, the N value is 9-7, and it gradually increases to -10m. The groundwater level is around GL-3.2m near the top of the fine sand layer.
In the Swedish sounding test result shown in FIG. 17 (b), there is an embankment of sandy soil of Nsw of 50 at most up to GL-0.5m, and the viscous soil near Nsw of 0 is below GL-4m. After that, except for a part, a sand layer with Nsw exceeding 100 continues.

The result of the construction test of the excavator in Examples 1 and 2 and the comparative example on the ground was as follows. FIG. 18 shows the relationship between the excavation depth for each excavator of each example and the excavator of the comparative example and the time required for excavation.
In the excavator of Example 1, the excavation speed decreased from the sand layer having an N value of about 6 of GL-4.5 m, but by performing an operation such as temporarily lifting the excavation rod on the way, the target GL- We were able to dig up to 8m. The time required to reach GL-8m from the start of excavation was 8.25 minutes.
In the excavator of Example 2, the excavation speed decreased from a sand layer of GL-4.5 m with an N value of about 6, but it was temporary, and it recovered to the original excavation speed in about 1 minute, and the target We were able to dig smoothly up to GL-8m. The time required to reach GL-8m from the start of excavation was less than 6 minutes.
The excavator provided with the excavating rod 1 of FIG. 15C did not perform the construction test, but the excavating rod 1 was provided with the conical head 21 and the spiral screw 3 was provided over the entire length of the excavating rod main body 1a. Since it has a soil function, it can be understood that the excavation performance is higher than that in Example 2 and the time required to reach a predetermined depth (GL-8 m) is further shortened.
The excavation device of the comparative example had the digging speed decreased from the sand layer of about GL-4.5 m with an N value of about 6, and seemed to be unable to dig at GL-5 m. The GL-6.3m fine sand layer was able to be excavated while continuing the excavation with operations such as temporarily pulling up. However, after that, it was not possible to dig at all, and it was not possible to dig up to the target GL-8m.

As a result of the construction test, the excavator of the comparative example (prior art) does not have the excavation mechanism of excavated soil, so that when the ground to be excavated becomes sandy soil, as shown in FIG. The indentation force works to increase the shear resistance of the sandy soil, and the excavation of the excavator is hindered, and the excavation to the target depth GL-8 m was not possible.
In the excavating apparatus according to the first embodiment of the present invention, since the soil removal mechanism of the spiral blade provided on the conical shape of the conical head 21 and the conical side face acts effectively, the excavation can proceed even if the ground to be excavated becomes sandy soil. Although the speed decreased, the digging was able to dig up to the target depth of GL-8 m without falling into the digging ability unlike the excavator of the comparative example. This is a sandy ground because the sandy soil excavated by the conical head 21 moves relatively upward, and the moved sandy soil is dug while the excavation rod 1 pushes it into the side ground. However, it is because excavated earth and sand do not become excavation resistance like a comparative example (prior art).
In the excavation apparatus according to the second embodiment of the present invention, since the section 1 m further above the conical head 1 is the spiral rod 1c provided with the spiral screw 3, the excavation force of the excavated soil is the excavation force of the first embodiment. It is stronger than the device. Moreover, since the earth and sand moved relatively upward is pushed sideways in the wide range of the spiral rod 25 and the excavation rod main body 1a thereabove, the excavation resistance is relative even if the excavation target ground is sandy soil. Become smaller. Therefore, the excavation apparatus of Example 2 is more reliable and smooth in digging to the target depth GL-8 m than the apparatus of the comparative example and Example 1, and the excavation time required to reach the target depth is the excavation time of Example 1. It was a little less than 6 minutes, which is 2 minutes or more shorter than the apparatus. This means that the construction time per one can be shortened by about 25% or more compared to the first embodiment.
The excavator provided with the excavating rod 1 shown in FIG. 15 (c) was not subjected to the construction test, but provided with the conical head 21 and the spiral screw 3 over the substantially entire length of the excavating rod main body 1a. Since it has a soil function, it can be predicted that the excavation performance is higher than that of Example 2 and the time required to reach a predetermined depth can be further shortened.

  According to the above construction test results, in terms of excavation performance, the excavator provided with the excavating rod 1 shown in FIG. 15 (c) is preferable, but this requires processing because excavated soil is discharged. Become. Considering that there is excavation performance and that no soil is generated, the excavator of Example 2 is most preferable. Further, in the excavator of the first embodiment, the excavation rod body 1a of the excavation rod 1 has a flat side surface and does not have a soil removal function, but the excavation head is the conical head 21 according to the present invention. Excavation performance is slightly inferior to 2, but excavation is possible even in sandy soil.

The spiral screw 3 of the spiral rod 1c of the excavator of Example 2 is preferably connected so as to be continuous with the spiral blade 25 of the conical head 21 from the viewpoint of making the soil removal mechanism more effective.
Increasing the length of the spiral rod 1c improves excavation performance, but tends to increase the amount of generated residual soil.
In the detached house foundation and the soil slab foundation, which are the main applications of the present invention, since it is common to use a small construction machine, the length of the excavation rod is about 4 m at the maximum, and a depth deeper than that The construction of the hydraulic solidifying material liquid replacement column is performed by adding the mounting rod 1b to the construction machine. Since the excavation rod 4m is composed of the spiral rod 1c and the excavation rod main body 1a having no earth removal mechanism on the side surface, the length of the spiral rod 1c should not exceed 2 m in terms of balance. Furthermore, about 1 m or less is preferable from the viewpoint of the amount of soil discharged and the kneading effect of the hole wall.

  In the above embodiment, the conical head 21 is detachably connected to the lower end portion of the excavating rod 1. However, the above-described maintenance, inspection, etc., and the case where no parts need to be replaced or these operations are described. 1 can be easily implemented from the outside of the joint 40 or the conical head 21, as shown in FIGS. 1 to 3, using the fastener P, the conical head 21 is not detachable from the joint 40. They may be fixedly connected (fixed) to each other by welding. 19 and 21 show a conical head 21 that is fixedly connected to the lower end of the excavation rod 1 (for example, by welding) directly without using the joint 40.

  In FIG. 19, the conical head 21 is fixedly connected to the lower end of the excavating rod 1 provided with the inner pipe 5 serving as a supply path for cement milk in the hollow by welding, for example, groove welding. By such groove welding, the excavation rod 1 and the conical head 21 are used as a base material and welded so as to build up in a groove (groove) such as a V shape or a U shape formed therebetween. Therefore, the excavating rod 1 and the conical head 21 can be fixedly connected so that a sufficient strength can be obtained quickly and easily. Here, the groove has a V shape.

In addition, using the excavation rod 1 fitted (detachable or fixed) with the conical head 21 having the spiral blades 25 on the peripheral surface as the excavation head, the hydraulic solidification liquid replacement column is constructed in the sandy ground. If it repeats, excavation head 21 and excavation rod 1 will be worn by excavation resistance of sandy ground. The wear situation is as follows. 25A and 25B will be described. FIGS. 25 (a) and 25 (b) are front views of the main part for explaining the state of wear of the conical head (excavation head) and the excavation rod. FIG. 25 (a) shows a state before wear, and FIG. Show.
(A) By repeating the construction in the sandy ground, the portion 41 protruding from the upper end portion 21c of the conical head 21 on the lower end surface of the excavating rod 1 is shown in the state of FIG. 25 (b) from the state of FIG. As such, it wears intensely and tries to approach the ridgeline of the conical head 21. In particular, the lower end portion 42 of the excavation rod 1 in contact with the upper end (end) of the spiral blade 25 of the conical head 21 is a portion through which the excavated earth and sand guided relatively upward along the spiral blade 25 passes. Therefore, the wear is severe.
(B) Since the excavated earth and sand is guided relatively upward along the spiral blade 25 of the conical head 21, the circumferential surface 43 of the conical head 21 near the upper end (terminal) of the spiral blade 25 of the conical head 21 is guided. It becomes a passage where the earth and sand are concentrated, and the excavation resistance of the excavation earth and sand is intense, and it wears intensely in this part.
(C) A lower peripheral side surface 44 of the excavation rod 1, particularly a section of 0.5 to 1 m from the lower end, is a portion that rotates and presses the excavation earth to the side to form a hole wall. Since the earth and sand guided by the spiral blades 25 of the conical head 21 are concentrated, it becomes a part that receives intense excavation resistance when it is rotationally pressed (slided), and is severely worn.
When such wear progresses, the function deteriorates, the conical head 21 or the excavation rod 1 breaks, and the construction of the hydraulic solidifying material liquid replacement column may be hindered, and the construction itself may become impossible. There is also.

  For example, in the work of building the hydraulic solidifying material liquid replacement column in the sandy ground, at the site where the spiral blade 25 is worn, the excavated soil cannot be pushed up quickly and smoothly during the excavation work, and the excavation efficiency is lowered. Further, the lower end of the excavation rod 1 is worn so as to follow the ridge line of the cone of the conical head 21, so that the hole wall forming property due to the hole wall pressing is reduced, and the excavation rod 1 and the conical head 21 are broken. Eventually, the construction of the hydraulic solidifying material liquid replacement column itself becomes impossible.

An embodiment for solving such a problem will be described with reference to FIGS.
FIG. 20 is a front view showing another embodiment of the conical head, and shows a case where a built-up portion N is formed by welding on the upper peripheral surface of the conical head 21 by welding.
In the conical head 21, the diameter increases toward the upper part, and the earth and sand are guided relatively upward along the spiral blade 25, so that the upper peripheral surface of the conical head 21 is easily worn. By providing the built-up portion N on the upper peripheral surface of the conical head 21 as in this example, it is possible to extend the life and extend the life. Moreover, when it wears down by use, the build-up part N can be formed in this partial peripheral surface by welding, and it can be reused.

FIG. 21 is a front view showing another form of the conical head, in which the spiral blade 25 is provided in a region not reaching the position of the upper end portion 21c of the conical head 21, and the conical head 21 shown in FIG. The outer diameter at the position of the upper end portion 21 c of 21 and the outer diameter of the excavation rod 1 are made the same size so that the spiral blade 25 does not reach the position of the upper end portion 21 c of the conical head 21. That is, a distance (interval) K is set between the upper end of the spiral blade 25 and the position of the upper end portion 21 c of the conical head 21 so that the spiral blade 25 does not reach the position of the upper end portion 21 c of the conical head 21.
According to this embodiment, since there is no portion protruding from the upper end portion 21c of the conical head 21 on the lower end surface of the excavating rod 1, wear deformation such that this portion is worn and approaches the ridgeline of the conical head 21c is reduced. . Further, since the spiral blade 25 does not reach the position of the upper end portion 21 c of the conical head 21, there is a distance between the upper end of the spiral blade 25 and the lower end of the excavation rod 1. Accordingly, the excavated earth and sand that is guided and moved along the spiral blade 25 is dispersed during the distance, and there is no portion that passes through the lower end of the excavating rod 1 in a concentrated manner. Is done.

FIG. 22 is a front view showing another embodiment of the conical head, and the overlay N is formed in a region a (hereinafter referred to as a wear region a) from the position of the upper end 21c of the conical head 21 to the upper end of the spiral blade 25. The case where it gave is shown.
The wear area a from the position of the upper end portion 21c of the conical head 21 to the upper end of the spiral blade 25 is most susceptible to excavation resistance in sandy ground or the like, and wear is likely to proceed in this area a, leading to strength deterioration of the conical head 21. easy. Therefore, the welded portion N is formed in the region a to extend the life, and when the region a is worn due to use, the cone head 21 can be reused by regenerating by buildup welding. It becomes possible, and long-term use becomes possible.
That is, as in the conical head 21 shown in FIG. 21, when the upper end of the spiral blade 25 does not reach the upper end portion 21c of the conical head 21 and the distance K is set, the spiral blade 25 is guided along the spiral blade 25. Since the excavated earth and sand passes over the upper end of the spiral blade 25 and is dispersed on the peripheral surface between the distances K of the conical head 21, the peripheral surface is heavily worn. According to the present embodiment, since the built-up portion N is formed on the peripheral surface (wear region a) between the distance K of the conical head that is heavily worn, the wear can be delayed and the life can be extended. Can do. Further, when worn out, it is possible to reuse by forming the built-up portion N by welding as shown in FIG.

FIG. 23 is a front view showing another embodiment of the present invention, and shows a case where a built-up portion N is applied to the wear region b of the lower peripheral surface of the excavating rod 1.
The lower peripheral surface of the excavating rod 1 is a portion that rotates the excavated earth to the side to form a pressing hole wall, and because the earth and sand guided by the spiral blades 25 of the conical head 21 are concentrated, It becomes a part that receives severe digging resistance when rotating (sliding) and wears violently. In particular, wear in a section of 0.5 to 1 m from the lower end of the lower peripheral surface of the excavation rod 1 is significant. According to the embodiment shown in FIG. 23, the build-up portion N is formed by welding on the lower peripheral surface (wear region b) of the excavating rod 1, for example, on the peripheral surface of the section 0.5 to 1 m from the lower end. Therefore, wear can be delayed and the life can be extended. When worn and used, the built-up portion N can be formed in the wear region b and reused.
In addition, instead of increasing the tube thickness of the wear region b on the lower peripheral surface of the excavation rod 1 by forming the build-up portion N by welding, the wear region on the lower peripheral surface of the excavation rod 1 from the beginning. You may use the rod with thick pipe | tube thickness of the part of b.

FIG. 24 is a front view showing another embodiment of the present invention. The distance K from the position of the upper end 21c of the conical head 21 to the upper end of the spiral blade 25 (wear region a) and the lower circumference of the excavating rod 1 are shown. This is a case where the built-up portion N is applied to the side surface (wear region b).
As described above, when the upper end of the spiral blade 25 does not reach the upper end 21c of the conical head 21 and there is a distance K between the upper end 21c, the peripheral surface (wear region a) between the distances K is present. Wears intensely. In addition, as described above, the lower circumferential surface (wear region b) of the excavating rod 1 is severely worn. According to the present embodiment, since the welded portion N is formed in the wear region a of the conical head 1 and the wear region b below the excavating rod 1, wear can be delayed and the life can be extended. . In addition, when the wear regions a and b are worn by use, they can be reused by forming the build-up portion N by welding, and the economic efficiency is improved.

  The present invention can prevent the vertical bearing force from being lowered due to the high depth of construction and the remaining in the replacement column of viscous soil, and has the effect of being able to excavate even in sandy soil with high excavation performance. The present invention is useful for excavating heads for excavating rods for building hydraulic solidified material liquid-displacement columns used for constructing small-diameter pile-shaped reinforcing materials by liquid replacement, and excavating apparatuses equipped with excavating rods connected to the excavating head.

1 Drilling rod 1a Drilling rod body 5 Inner pipe (supply pipe)
21 Conical head 21a Base 21b Conical part 22 Flow path (communication hole)
22a Discharge port 23, 24 Check valve 25 Spiral blade 26 Countersink 27, 29, 31 Insertion hole 28 Steel plate 30 Steel rod 32 Bucket (hydraulic solidifying material liquid receiver)
33 Suspension string 34 Hook 35, 37, 38 Protrusion 40 Joint N Overlaying part

Claims (16)

  A drilling head of a drill rod for building a hydraulic solidifying material liquid replacement column, which is provided at a lower end portion of the drilling rod having a flow path of a hydraulic solidifying material liquid and projecting conically downward. In addition, the peripheral surface of the conical head is provided with a discharge port for hydraulic solidifying material liquid leading to the flow path, and a spiral blade is provided in a direction to push up the excavated earth and sand at the time of normal rotation of the excavating rod. Drilling head for drill rod for building hydraulic solidification liquid replacement column.   2. The excavation head for a drill rod for building a hydraulic solidifying material liquid replacement column according to claim 1, wherein the maximum outer diameter of the conical head during rotation does not exceed the rotation diameter of the excavation rod.   The excavation head for an excavation rod for building a hydraulic solidifying material liquid replacement column according to claim 1 or 2, wherein a build-up portion formed by welding is formed on an upper peripheral surface of the conical head. .   4. The excavation rod for excavating a hydraulic solidifying material liquid replacement column according to claim 1, wherein an outer diameter of an upper end portion of the conical head is substantially the same as an outer diameter of the excavation rod. head.   5. The hydraulic solidified material according to claim 1, wherein the spiral blade provided on the peripheral surface of the conical head is provided in a region not reaching an upper end portion position of the conical head. Drilling head for drilling rod for liquid replacement column construction.   6. The excavation for building a hydraulic solidified material liquid replacement column according to claim 5, wherein a peripheral surface from an upper end position of the conical head to an upper end of the spiral blade is a built-up portion built up by welding. Rod drilling head.   The excavation head of the excavation rod for building a hydraulic solidifying material liquid replacement column according to any one of claims 1 to 6, wherein the excavation rod and the conical head are connected by welding.   8. The excavation head for an excavation rod for constructing a hydraulic solidification material liquid replacement column according to claim 1, wherein a check valve is provided at a discharge port of the hydraulic solidification material liquid.   The discharge port of the hydraulic solidifying material liquid is machined to a height lower than the conical surface of the conical head by cutting the rear side in the rotational direction during excavation rotation of the excavation rod from the center position. A drilling head for a drilling rod for building a hydraulic solidifying material liquid replacement column according to any one of 1 to 8.   10. The hydraulic solidifying material liquid replacement column construction according to claim 1, wherein a projection or a hole for hanging the hydraulic solidifying material liquid receiving member is provided at the forefront of the conical head. Drilling head of the drilling rod.   11. A drilling apparatus for building a hydraulic solidifying material liquid replacement column, wherein the drilling head according to any one of claims 1 to 10 is connected to a lower end portion of a drilling rod.   The excavation apparatus for building a hydraulic solidified material liquid replacement column according to claim 11, wherein the excavation rod is an unequal thickness pipe having a large thickness in a range of at least 0.5 m from the lower end.   The excavation rod for excavation for building a hydraulic solidified material liquid replacement column according to claim 11 or 12, wherein the excavation rod has a wear portion on a lower peripheral surface formed in a build-up portion formed by welding. apparatus.   A spiral screw with an outer diameter equal to or slightly smaller than the diameter of the excavating rod body and pushing the excavated earth and sand upward during forward rotation is provided at the lower part of the excavating rod body with a smooth peripheral surface without a soil removal mechanism. A hydraulic solidifying material liquid comprising: a relatively short spiral rod connected to each other; and a drill rod connected to the drill head according to any one of claims 1 to 10 at a lower end of the spiral rod. Drilling rig for building replacement columns.   The excavation apparatus for building a hydraulic solidifying material liquid replacement column according to claim 14, wherein the length of the spiral rod does not exceed 2 m at most.   The excavation head according to any one of claims 1 to 10 is connected to a lower end of a excavation rod main body provided with a spiral screw in a direction of pushing up excavation earth and sand upward during the normal rotation over substantially the entire length of the peripheral surface. A drilling device for constructing a hydraulic solidifying material liquid replacement column, comprising a drilling rod.

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