JP5757159B2 - Casing installation method, and support bracket and vibro hammer used therefor - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a casing installation method used when forming a cast-in-place concrete pile in the ground, and a support bracket and a vibro hammer used therefor.

  Conventionally, as a foundation of a building structure, it has been widely performed to form a concrete pile in the ground. One method of forming concrete piles is to insert a cylindrical casing into the ground, excavate the inside of the casing, place reinforcing bars inside the excavated holes, and place concrete. (For example, refer to Patent Document 1).

  Here, in order to penetrate the casing into the ground, a vibro hammer method is generally used. In the vibratory hammer method, the main part of the vibratory hammer generating vibration force is suspended by a crane, and vibration is applied to the casing while the upper part of the casing is chucked by the chucked part of the vibratory hammer. Then, the frictional force and resistance force generated around the casing and between the tip and the ground are reduced, and the casing and the vibro hammer are easily weighted so that the casing can easily penetrate into the ground.

JP 2005-273411 A

  However, when using a casing having a length of 10 to 20 m or the like, the weight of the casing increases, so that there is a possibility that the holding capacity (weight that can be held) in the chuck portion of the vibro hammer may be exceeded. .

  In addition, at the foundation construction stage, the ground is exposed at the site, and mud etc. are likely to adhere to the casing. In particular, in the case of rain, etc., if mud or the like adheres to the casing, the casing chucked by the chuck portion is easy to slip, and the above problem becomes more remarkable.

  Therefore, the present invention has been made in view of the above circumstances, and provides a casing installation method capable of reliably holding a casing, and a support bracket and a vibro hammer used therefor.

The present invention employs the following means in order to solve the above problems.
That is, the present invention is a method of installing a cylindrical casing for earth retaining at a position where the concrete pile is to be formed when the concrete pile is formed in the ground. The vibro hammer is suspended by a lifting machine while being held by a plurality of chuck portions, and the casing is connected to the lifting machine or the vibro hammer by a rope, and the casing should be installed by the lifting machine And moving the casing to the ground while transferring the vibration generated in the main body of the vibrator hammer to the casing via the chuck portion.

  Thus, the casing is not only held by the chuck portion of the vibro hammer, but is also connected to the lifting machine or the vibro hammer by the rope. Therefore, even if the holding capability at the chuck portion is insufficient, the casing can be prevented from falling off by the rope, and the casing can be reliably held.

  Further, the casing may be connected to a support bracket set in a detachable state with respect to the main body via the cable body.

  Thereby, it can implement by only attaching a support bracket to the main-body part of a vibro hammer, without processing the main-body part of a vibro hammer.

  Furthermore, the present invention provides a support attached to the body portion of a vibro hammer that vibrates a cylindrical casing for earth retaining that penetrates the ground at a position where the concrete pile is to be formed when the concrete pile is formed in the ground. A bracket, comprising: a support plate placed on the upper surface of the main body portion; and a side plate extending downward along the side surface of the main body portion from the support plate, and a locking tool is provided on the side plate. It is provided, The above-mentioned locking tool and the upper end part of the above-mentioned casing can be connected with a cable body, It is characterized by the above-mentioned

  The vibro hammer according to the present invention, when forming a concrete pile in the ground, a chuck portion that holds an upper end portion of a cylindrical casing for earth retaining that is inserted into the ground at a position where the concrete pile is to be formed. And a support body according to claim 3 provided integrally with the main body portion, and a main body portion incorporating a vibration mechanism for vibrating the casing via the chuck portion. It is a feature.

  According to the present invention, the casing is not only held by the chuck portion of the vibro hammer, but is also connected to the lifting machine or the vibro hammer by the rope body. However, it is possible to prevent the casing from falling off by the cable body and to hold the casing reliably.

It is a figure which shows the construction method of the cast-in-place concrete pile in 1st embodiment, Comprising: (a) is a schematic block diagram (front view), (b), (c) is the partial expansion perspective view of a casing. . It is a front view which shows the state which suspended the casing in 2nd embodiment.

  Hereinafter, with reference to the accompanying drawings, a method for installing a casing according to the present invention, and a support bracket and an embodiment for implementing a vibro hammer used therein will be described. However, the present invention is not limited only to these examples.

(First embodiment)
As shown in FIG. 1, when forming a cast-in-place concrete pile, in order to penetrate the cylindrical casing 10 into the ground, a vibro hammer 20 is used.

The vibro hammer 20 is suspended from a hook 30 of a crane (lifter) by a wire W1. The vibro hammer 20 includes a main body portion 21 having a built-in vibration mechanism that generates a vibration force, and a pair of chuck portions 22 and 22 provided to protrude downward from the main body portion 21.
Each chuck portion 22 is driven to open and close by hydraulic pressure or the like so that the chuck can be held with the upper end portion of the casing 10 interposed therebetween. Each chuck part 22 is connected to a vibration mechanism built in the main body part 21 so that vibrations generated by the vibration mechanism are transmitted.

  The casing 10 is held by chucking its upper end portion with a pair of chuck portions 22 and 22.

  Further, the casing 10 held by the chuck portions 22 and 22 is configured to be able to connect a wire (cord) W2. Specifically, as shown in FIGS. 1 (b) and 1 (c), a pair of locking tools 11, 11 are provided in the vicinity of the upper end portion of the casing 10. The end of a chain or wire (hereinafter simply referred to as a wire) W <b> 2 suspended on the wire can be connected.

  Here, as the locking tool 11, for example, as shown in FIG. 1B, for example, a circular ring 13 is passed through a hole 12 a formed in the stay 12 welded and fixed to the outer peripheral surface of the casing 10. For example, as shown in FIG. 1C, a through-hole 10a formed near the upper end of the casing 10 and having a ring 14 having a triangular shape in front view can be used.

  The wire W <b> 2 can be stretched between the hook 30 and the pair of locking tools 11 and 11 in a state in which a predetermined tension is exerted in a state where the casing 10 is held by the chuck portions 22 and 22. Alternatively, in a state where the casing 10 is held by the chuck portions 22, 22, the wire W <b> 2 can be hung between the hook 30 and the locking tool 11 with a margin so that no tension is generated in the wire W <b> 2.

As described above, the casing 10 is configured such that the upper end portion thereof can be suspended from the crane hook 30 via the vibro hammer 20 and the wire W2. As a result, the casing 10 can be suspended with its axis line positioned in the vertical direction.
In this state, the suspended casing 10 can be positioned vertically above a predetermined position where the concrete pile is to be formed by turning and extending / contracting the boom (not shown) of the crane.

  Subsequently, the hook 30 is lowered and the lower end portion 10b of the casing 10 is placed on the ground G. In this state, the vibration mechanism of the main body portion 21 of the vibro hammer 20 is operated to vibrate the chuck portions 22 and 22. Then, vibration is transmitted to the casing 10 via the chuck portions 22 and 22.

  When the crane hook 30 is gradually lowered, the casing 10 penetrates into the ground by the weight of the casing 10 and the vibro hammer 20. At this time, the casing 10 is vibrated by the vibration mechanism of the main body portion 21 of the vibro hammer 20, whereby the frictional force and the resistance force generated around the casing 10 and between the lower end portion 10 b and the ground G are reduced. Becomes easier to penetrate into the ground.

  When the casing 10 is penetrated to a predetermined depth in the ground G in this way, the chuck by the chuck portions 22 and 22 of the vibro hammer 20 is released and the wire W2 is removed from the locking tool 11. And the vibro hammer 20 is pulled up with the hook 30 of the crane, and the casing 10 is left in the ground G.

  Thereafter, the ground G inside the casing 10 is excavated, a reinforcing bar is arranged inside the excavated hole, and concrete is placed. Thereby, a concrete pile can be formed with cast-in-place concrete inside the casing 10 while earth retaining the surrounding ground G. In addition, the casing 10 can be drawn out before the placed concrete is hardened, and can be diverted to the formation of other concrete piles in the same manner as described above.

  According to the above configuration, the casing 10 is chucked and held by the chuck portions 22 and 22 of the vibro hammer 20 suspended from the crane hook 30, and the wire W2 suspended from the crane hook 30 is casing. 10 is locked. Accordingly, the casing 10 is chucked and held by the chuck portions 22 and 22 of the vibro hammer 20 in a normal state, and if the chuck cannot be held by the chuck portions 22 and 22, the casing 10 is suspended and held by the wire W2. Can do. In this way, the casing 10 can be reliably held.

  At this time, as the locking tool 11 for locking the wire W2, as shown in FIG. 1 (c), a case in which the ring 14 is passed through the through hole 10a formed in the upper end portion of the casing 10 is used. The through hole 10a may be formed in advance so as to cause the casing 10 to be raised from a material storage place for temporary storage. Thereby, the said effect can be acquired at low cost.

(Second embodiment)
Next, a second embodiment of the present invention will be described. In the second embodiment described below, the wire W2 is suspended from the vibrator hammer 20 instead of the crane hook 30. Therefore, in the following description, components that are the same as those in the first embodiment are given the same reference numerals, and descriptions thereof are omitted.

As shown in FIG. 2, the casing 10 is chucked and held by chuck portions 22 and 22 of a vibro hammer 20 suspended from a hook 30 of a crane by a wire W1.
Further, the casing 10 is suspended from a support bracket 50 attached to the main body 21 of the vibro hammer 20 by a wire (cord) W3.

  Here, the support bracket 50 may have any configuration. For example, the support plate 51 placed on the upper surface of the main body 21 of the vibro hammer 20 and the side surfaces of the main body 21 from both ends of the support plate 51. Are connected to each other, side plates 52, 52 that hang down along the horizontal plate 53, horizontal plates 53, 53 extending horizontally from the lower ends of the side plates 52, 52, and horizontal plates 53, 53 on both sides of the main body 21. And a connecting plate 54 along the side surface 21b of the main body 21.

  A through hole 55 is formed at an appropriate location of the support bracket 50, for example, at the lower end of the side plate 52, and a shackle 56 is hooked on the through hole 55. The wire W3 is stretched between the shackle 56 and the locking tool 11.

  The wire W3 can be stretched between the shackle 56 and the locking tool 11 in a state in which a predetermined tension is exerted in a state where the casing 10 is held by the chuck portions 22 and 22, but the casing 10 is chucked. In the state held by the portions 22 and 22, the wire W <b> 3 may be stretched between the shackle 56 and the locking tool 11 with a margin so that no tension is generated in the wire W <b> 3.

  According to the configuration of the present embodiment, as in the first embodiment, the casing 10 is chucked and held by the chuck portions 22 and 22 of the vibro hammer 20 suspended from the hook 30 of the crane. The wire W3 suspended from the main body 21 is locked to the casing 10. Thus, the casing 10 is chucked and held by the chuck portions 22 and 22 of the vibro hammer 20 in a normal state, and if the chuck cannot be held by the chuck portions 22 and 22, the casing 10 is suspended and held by the wire W3. Can do. In this way, the casing 10 can be reliably held.

  Further, the wire W <b> 3 is suspended from the support bracket 50 installed on the main body portion 21 of the vibro hammer 20. This eliminates the need to lock the wire W3 to the hook 30 of the crane located above the main body 21 of the vibro hammer 20, and it is sufficient to hang the wire W3 on the shackle 56 located immediately above the casing 10. It can be done easily and efficiently.

The support bracket 50 can be easily installed on the main body 21 of the vibro hammer 20. In an actual site, a rental product is often used as the vibro hammer 20, but even if it is a rental product, the vibro hammer 20 can be prevented from being damaged.
Of course, when the vibro hammer 20 is not a rental product, the support bracket 50 may be omitted, and the wire W3 may be chucked and held by the shackle 56 provided directly on the main body 21 of the vibro hammer 20.

(Other embodiments)
The casing installation method of the present invention, and the support bracket and vibro hammer used therefor are not limited to the above-described embodiments described with reference to the drawings, and various modifications are possible within the technical scope thereof. Conceivable.

For example, the configuration of the support bracket 50 is not limited to that illustrated in FIG. 2 and may be any other configuration as long as the same function is achieved.
As the member used for locking the wires W2 and W3, those other than those exemplified above can be used.
In addition to this, the configuration described in the above embodiment can be selected or changed to another configuration as appropriate without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 10 ... Casing 10a ... Through-hole 10b ... Lower end part 11 ... Locking tool 12 ... Stay 12a ... Hole 13 ... Ring 14 ... Ring 20 ... Vibro hammer 21 ... Main-body part 22 ... Chuck part 30 ... Hook (lifter) 50 ... Support Bracket 51 ... Support plate 52 ... Side plate 53 ... Horizontal plate 54 ... Connection plate 55 ... Through hole 56 ... Shackle G ... Ground W1 ... Wire W2 ... Wire (Rope) W3 ... Wire (Rose)

Claims (3)

When forming a concrete pile in the ground, a method of installing a cylindrical casing for earth retaining at a position where the concrete pile should be formed,
Suspending the vibro hammer with a lifting machine while holding the upper end of the casing with a plurality of chuck parts of a vibro hammer, and connecting the casing to the lifting machine or the vibro hammer with a rope;
A step of moving the casing to a position where the casing is to be installed by the lifting machine and penetrating the casing into the ground while transmitting vibration generated in a main body of the vibrator hammer to the casing via the chuck portion; and, the possess,
The casing is connected to a support bracket set so as to be detachable from the main body via the cable body . When forming a concrete pile in the ground, a support bracket attached to the body portion of a vibro hammer that gives vibration to a cylindrical casing for earth retaining that penetrates into the ground at a position where the concrete pile should be formed,
A support plate placed on the upper surface of the main body,
A side plate extending downward along the side surface of the main body from the support plate,
A support bracket, wherein a locking tool is provided on the side plate, and the locking tool and an upper end portion of the casing are connectable by a cable body. When forming a concrete pile in the ground, a chuck portion that holds an upper end portion of a cylindrical casing for earth retaining that penetrates into the ground at a position where the concrete pile should be formed,
A main body portion incorporating a vibration mechanism for vibrating the casing via the chuck portion;
A vibro hammer comprising: the support bracket according to claim 2 provided integrally with the main body.

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