JP5605940B2 - Construction management method of root-fixed bulb part and expansion excavator used therefor - Google Patents

Description

  The present invention confirms whether or not the expansion excavation by the expansion wing for forming the consolidation bulb portion has been reliably performed in the construction of the foundation pile that builds up the consolidation bulb portion by expanding the pile hole tip. Regarding technology.

  For example, by excavating the ground in the support layer using the medium excavation method or the pre-boring method, and by injecting the root hardening liquid (cement milk) into this expanded excavation part, a root bulb is constructed, and the tip of the ready-made pile In the expansion rooting method to increase the bearing capacity, as an expansion excavator, the expansion blades are switched from a reduced diameter state to an expanded state by earth pressure by rotating the excavating rod in reverse, or fluid pressure such as hydraulic pressure or hydraulic pressure is used. An expansion excavator of a type in which the expansion blade is switched between a reduced diameter state and an expanded diameter state by a cylinder is used.

  In any type, the enlarged blade must open only at the root and close when the drilling rod is lifted, so it is impossible to visually check whether the enlarged blade is actually open in the support layer. is there.

  In addition, if the construction is completed without the wings being fully opened in the ground, the construction of the root bulb will be incomplete, and the support force as designed will not be secured. It becomes a big problem of the whole thing. Therefore, there is a strong demand for a method for confirming whether or not the enlarged wing has actually opened in the ground, and various proposals have been made.

  For example, Patent Document 1 discloses a detector comprising a limit type micro switch, a substrate with a backup power source, and the like in the vicinity of an enlarged wing, and a hollow portion of a drilling rod that serves as a liquid supply path for a detection signal from the detector. A method of attaching a wireless transmitter for transmitting to the ground via the network is disclosed.

  Patent Document 2 discloses an expansion blade change detection means using an inclination sensor, a rotation sensor, a proximity sensor, and the like that electrically detects the operation of the expansion blade, a memory of detected data, and a microcomputer that controls them. A method is disclosed in which data is taken out after the excavation rod is lifted to raise the expansion excavator to the ground.

  Since these are methods that electrically detect the movement of the expansion wing, the expansion drilling device at the tip of the drilling rod rotates with the drilling fluid in the ground, and the hole wall is scraped off with the expanded wing. In a severe environment where the resistance due to vibration, water pressure, and excavated soil is large, there is a risk of failure and the reliability of the detection result is difficult.

  Further, in an enlargement excavator of a type in which an enlarged blade is switched between a reduced diameter state and an enlarged diameter state by a fluid pressure cylinder, a method of confirming that the enlarged blade is opened by a change in hydraulic pressure or water pressure may be adopted. However, this method requires piping for measuring hydraulic pressure or water pressure from the ground to the enlarged excavator, which is troublesome.

JP-A-6-212873 JP 2009-41315 A

  The present invention has been made in view of the above-mentioned problems, and the object of the present invention is simple, without worrying about failure even in a severe environment where vibration, water pressure, and pressure due to excavated soil are large. The configuration is to ensure that the enlarged wing is actually opened or not.

The technical means taken by the present invention in order to achieve the above object are as follows. That is, the construction management method of the root-clamping bulb portion according to the first aspect of the present invention is an enlargement in an enlargement excavation device that enlarges and excavates the tip end portion of a pile hole with an enlargement blade configured to be switchable between an enlarged diameter state and a reduced diameter state. a position overlapping the end position of the movable range of the wing, enlarged wing may be provided with confirmation member crushed expanded wings by switching to expanded state removably exchange, after pulling up the expanded drilling apparatus on the ground By confirming the deformation state of the confirmation member, it is confirmed that the expanding blade is actually opened, and the confirmation member is a cartridge type provided with a base plate .

  In addition, as a confirmation member, it is plastically deformed into a state where it is crushed by the expansion wing or a movable member interlocked with the expansion wing when the expansion wing opens when the expansion wing opens, and the hardness that can withstand vibration, water pressure and earth pressure during drilling For example, an iron pipe or an iron bar is preferable.

Invention of Claim 2 is an expansion excavation apparatus used for the construction management method of the root hardening bulb part by the invention of Claim 1, Comprising: The expansion wing | blade comprised so that switching to a diameter expansion state and a diameter reduction state was possible With the expansion excavator that expands the tip of the pile hole by using the expansion wing, the confirmation member that is crushed by the expansion wing can be removed and replaced at the position that overlaps the end position of the movable range of the expansion wing Ri attached Ah in the confirming member is characterized in that it is formed in the cartridge having a base plate.

  According to the first aspect of the present invention, it is possible to surely confirm whether or not the enlarged wings are actually opened by visually checking the deformation state of the confirmation member after lifting the enlarged excavator to the ground.

  In particular, since it is a simple configuration in which a confirmation member that is crushed by the enlarged wing when the enlarged wing is switched to the expanded state is provided at a position that overlaps the end position of the movable range of the enlarged wing in the enlarged excavator, It is extremely effective as a method of construction management for rooting bulbs because it can be confirmed with high reliability without worrying about failure even in harsh environments during excavation where large vibrations, water pressure, and earth pressure are applied. It is.

  According to the second aspect of the present invention, since the confirmation member is detachably attached, it can be used as a construction record for the rooted bulb portion by storing the deformed confirmation member. It is suitable for the construction management method of the root hardening bulb part described in 1.

It is explanatory drawing at the time of a pile hole excavation. It is explanatory drawing at the time of expansion excavation of a pile hole front-end | tip part. It is a front view of the expansion excavation apparatus which concerns on this invention. It is a cross-sectional top view of the expansion excavation apparatus in which an expansion blade is in a diameter reducing state. It is a cross-sectional top view of the expansion excavation apparatus in which an expansion blade is in a diameter expansion state. It is an expanded longitudinal cross-sectional view of the principal part of the expansion excavation apparatus in which the expansion blade is in a reduced diameter state. It is a perspective view of the member for confirmation. It is a perspective view which illustrates another member for confirmation. It is a partially broken front view in the expansion blade reduced diameter state of the expansion excavation apparatus which shows other embodiment of this invention. FIG. 10 is a partially broken front view of the expansion excavator shown in FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 and FIG. 2 show a construction example of a foundation pile in which a pile hole tip portion is expanded and excavated by a medium digging method to build a rooted bulb portion. In the figure, 1 is a ready-made pile, and 2 is a hollow excavation rod that is rotationally driven by an auger machine (not shown). A spiral blade 3 is provided on the outer periphery of the excavation rod 2, and the hollow portion is formed in a supply path for excavation liquid such as bentonite solution and root hardening liquid (cement milk).

  To the tip of the excavation rod 2, an enlargement excavator 4 for enlarging and excavating the tip of the pile hole to build a root-clamping bulb is connected so as to rotate integrally with the excavation rod 2. As shown in FIG. 3, the enlarged excavator 4 shown in the drawing includes a hollow drive shaft 5 communicating with the excavation rod 2 and a spiral shape provided on the outer periphery thereof (a spiral shape in the same direction as the spiral blade 3). Are provided along the spiral of each excavating blade 6 and can be switched between a diameter-expanded state and a diameter-reduced state. And two enlarged wings 8.

  The expansion blade 8 is supported by a pin 9 on a bracket 9 connected to the excavation blade 6 so as to be swingable. Then, during pile hole excavation in which the excavation rod 2 is rotated forward (rotation in the direction of arrow a shown in FIGS. 1 and 4), as shown in FIGS. 1 and 4, due to earth pressure (resistance due to excavated soil and hole walls) Then, the diameter of the excavation blade 6 is reduced and the diameter of the excavation blade 6 is accommodated, and the excavation rod 2 rotates in the reverse direction (rotation in the direction of the arrow b shown in FIGS. 2 and 5). Swing around the pin 10 in response to (resistance due to excavated soil or hole wall), as shown in FIG. 2 and FIG. 5, a diameter expansion state projecting radially outward from the rotation trajectory of the excavating blade 6 is achieved. It is configured.

  In the enlargement excavator 4, the enlargement blade 8 swings around the pin 10 at a position overlapping the terminal position of the movable range of the enlargement blade 8 and in the vicinity of the pin 10, thereby switching to the expanded diameter state. The confirmation member 11 to be crushed by is attached detachably and replaceably. As shown in FIGS. 6 and 7A, the confirmation member 11 is formed in a cartridge type having a flat base plate 11a, and the base plate 11a is formed as shown in FIGS. The confirmation member 11 is fixed to the inner surface of the bracket 9 and on the outer side of the pin 10 with a screw 12 so as to be positioned parallel to the pin 10.

  According to said structure, after excavating a pile hole to a support layer, by rotating reversely the excavation rod 2, the expansion wing | blade 8 switches to a diameter expansion state, and when excavating a pile hole front-end | tip part, FIG. As shown in FIG. 4, the expanding blade 8 swings around the pin 10 and switches to the expanded diameter state. In other words, when the expanding blade 8 is completely opened, the confirmation member 11 is pushed by the expanding blade 8. It will be crushed.

  Therefore, after the expansion excavator 4 is lifted to the ground, the deformation state of the confirmation member 11 can be confirmed visually to confirm whether or not the expansion blade 8 has actually opened in the ground. It is possible to know that the expanded excavation of the part (the construction of the root-clamping bulb part) has been carried out completely. In addition, since the confirmation member 11 is formed in a cartridge type that is detachable and replaceable, as shown in FIG. 9B, by arranging and storing the deformed confirmation member 11, the rooted bulb portion It can be used as a construction record.

In particular, since the confirmation member 11 that is crushed by the enlarged blade 8 when the enlarged blade 8 is switched to the expanded state is provided in a part of the enlarged excavator 4, a large vibration, water pressure, soil Even under harsh environments during pressure excavation, there is no risk of breakdown and high reliability can be confirmed. Therefore, it is extremely effective as a construction management method for root-tightening bulbs.

  The confirmation member 11 has both hardness that can withstand vibration, water pressure, and earth pressure during excavation of a pile hole, and softness that can be plastically deformed into a state of being crushed by the expansion blade 8 when the expansion blade 8 is opened. Since it is necessary, it is desirable that it is made of metal such as iron, aluminum, and copper. As the cross-sectional shape of the confirmation member 11, pipes such as a square pipe as shown in FIG. 8A are available as commercial products in addition to the circular pipe shown in FIG. Although it is preferable in terms of ease, the cross section as shown in FIGS. 8B, 8 </ b> C, and 8 </ b> D can be appropriately selected and implemented such as a metal rod having a quadrangular, circular, or triangular cross section.

  9 and 10 show another embodiment of the present invention. In this embodiment, the expansion blade 8 is swingably supported in the expansion excavator 4 of a type in which the expansion blade 8 is switched between a reduced diameter state and an expanded diameter state by a fluid pressure (water pressure or hydraulic pressure) cylinder built in the drive shaft 5. The base plate 11a of the confirmation member 11 is fixed to the bracket 9 to be screwed 12 and the enlargement blade 8 is switched to the expanded state so that the confirmation member 11 is crushed by the enlargement blade 8. There is. A protruding portion 8a protruding to the opposite side of the pin 10 is formed at the base portion of the expanding blade 8, and the confirmation member 11 is crushed by the protruding portion 8a. Other configurations and operations are the same as those of the embodiment of FIGS.

  It should be noted that the present invention is not limited to the method of expanding the tip of the pile hole by the medium excavation method and constructing the rooted bulb portion, but also by constructing the root bulb portion by the pre-boring method to increase the tip bearing capacity of the ready-made pile. It can also be used in the same way for the expanded deepening method and the deepening cast-in-place pile method that builds the rooted bulb at the tip of the cast-in-place pile.

DESCRIPTION OF SYMBOLS 1 Ready-made pile 2 Excavation rod 3 Spiral blade 4 Expansion digging device 5 Drive shaft 6 Excavation blade 7 Excavation blade 8 Expansion wing 9 Bracket 10 Pin 11 Confirmation member 11a Base plate 12 Screw

Claims (2)

The expansion blade is switched to the expanded state at a position that overlaps the end position of the movable range of the expansion blade in the expansion drilling device that expands the tip of the pile hole with the expansion blade that can be switched between the expanded diameter state and the reduced diameter state. By installing a confirmation member that can be crushed by the expansion wing in exchange , detachable and replaceable , pulling the expansion excavator up to the ground, and confirming the deformation state of this confirmation member, the expansion wing is actually opened. A construction management method for a root compaction bulb , wherein the confirmation member is a cartridge type having a base plate . The expansion blade is switched to the expanded state at a position that overlaps the end position of the movable range of the expansion blade in the expansion drilling device that expands the tip of the pile hole with the expansion blade that can be switched between the expanded diameter state and the reduced diameter state. Oh Ri attached to confirming member to be crushed expanded wings detachably replaced by switched, the confirmation member is expanded drilling apparatus characterized by being formed on the cartridge type provided with a base plate.

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