JP5137682B2 - Simple loading test method - Google Patents

Description

  The present invention relates to a simple loading test method, and more particularly to a simple loading test method using a pile press-in machine, which is performed in order to clarify the support force of a pile in the construction of a support pile.

Conventionally, a loading test for measuring a supporting force of a steel pipe pile buried in the ground has been performed.
Specifically, a load test attachment attached to an existing pile arranged in parallel with a pile subject to a load test performs a load test by applying a load that pushes down the test pile (for example, a patent Reference 1) and the existing piles on both sides of the pile subject to the load test are held by the clamp unit, so that the load unit of the load test apparatus is arranged in the pile to be tested. A technique (for example, see Patent Document 2) in which a load test is performed by applying a load that pushes down the load is known.
JP 2003-27518 A JP 2004-204484 A

However, in the case of the above prior art, after the press-in construction of a predetermined pile is completed, the load test attachment and the load test device are installed on the pile and the load test is performed. Therefore, the load test attachment and device are installed. Since it takes time and effort to remove, the construction period and cost may increase.
In addition, when a load test is performed using an existing pile that has undergone press-fitting construction and a load is applied to push down the test target pile from the existing pile, the reaction force acting on the existing pile is applied to the existing pile. Since it acts as a pulling force, there is a concern that the existing pile may be pulled up, and as a result, there is a concern that the supporting force is not expressed. And if you do not want to apply the pulling force to the existing pile, you may install a temporary pile for testing, but it takes time to install and remove the temporary pile, which increases the work period and cost There was a thing.

  An object of the present invention is to provide a simple loading test method that enables an easier loading test.

In order to solve the above problems, the invention described in claim 1 is a simple loading test method,
The reaction force is taken from the existing pile by a plurality of clamping devices that support the upper end side of the existing pile press-fitted or rotationally pressed into the ground, and the pile is lined up by gripping and lowering the pile with a liftable lift chuck device In the process of connecting multiple piles, using a pile presser that press-fits or piles new piles in position,
With respect to the existing pile on which the reaction force has been taken and the pulling force has been applied, a pressure input is again loaded by the pile presser in the final step of construction, and a supporting force is developed in the existing pile, The support force is confirmed.

The invention according to claim 2 is a simple loading test method,
The reaction force is taken from the existing pile by a plurality of clamping devices that support the upper end side of the existing pile press-fitted or rotationally pressed into the ground, and the pile is lined up by gripping and lowering the pile with a liftable lift chuck device In the process of connecting multiple piles, using a pile presser that press-fits or piles new piles in position,
Among the plurality of clamp devices, a load is applied to a predetermined existing pile supported by the clamp device by a loading mechanism provided in the clamp device arranged farthest from the chuck device.

The invention according to claim 3 is a simple loading test method,
The reaction force is taken from the existing pile by a plurality of clamping devices that support the upper end side of the existing pile press-fitted or rotationally pressed into the ground, and the pile is lined up by gripping and lowering the pile with a liftable lift chuck device In the process of connecting multiple piles, using a pile presser that press-fits or piles new piles in position,
A load is applied to a predetermined existing pile by a loading mechanism provided in an arrangement on the opposite side of the chuck device with the plurality of clamping devices interposed therebetween.

The invention according to claim 4 is the simple loading test method according to claim 2 or 3,
The plurality of clamping devices support the existing piles, and the chuck device grips a new pile that is press-fitted or rotationally pressed into the ground, and applies a load to the predetermined existing pile by the load mechanism described above, and loads It is characterized by conducting a test.

The invention according to claim 5 is the simple loading test method according to any one of claims 2 to 4,
A load test is performed by applying a load to the existing piles press-fitted or rotationally press-fitted by the pile press-fitting machine by the load mechanism section described above.

The invention according to claim 6 is a simple loading test method,
The reaction force is taken from the existing pile by a plurality of clamping devices that support the upper end side of the existing pile press-fitted or rotationally pressed into the ground, and the pile is lined up by gripping and lowering the pile with a liftable lift chuck device In the process of connecting multiple piles, using a pile presser that press-fits or piles new piles in position,
A load test is performed by applying a load to the existing pile by the chuck device.

According to the present invention, the pile press-in machine used for the simple loading test includes the loading mechanism portion that applies a load to the existing pile supported by the clamp device or the like. A load test can be easily performed by applying a load to the existing pile.
And, in the process of connecting a plurality of piles using this pile press-in machine, a simple load test can be performed by applying a load to the existing pile to be loaded by the pile press-in machine. After the test is completed, it is possible to save the trouble of installing and removing the loading test device on the pile, and the trouble of installing and removing the temporary pile for testing. It becomes possible to perform a loading test.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a pile press-fitting machine and a pile simple loading test method using a pile press-fitting machine according to the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
As shown in FIG. 1, the pile press-in machine 10 is a press-fit machine that press-fits a predetermined pile (for example, a steel pipe pile or the like) into the ground G or rotationally press-fits (hereinafter simply “press-fit”). A saddle 12 provided with a plurality of (for example, three) clamping devices 11 for holding and supporting the upper end of the existing pile P, a slide base 13 movable back and forth with respect to the saddle 12, and a slide base 13 The reader mast 14 can be turned right and left, the chuck device 15 is attached to the front surface of the reader mast 14 so as to be movable up and down, the main hydraulic cylinder 16 that drives the chuck device 15 up and down with respect to the leader mast 14 and the like.

The clamp device 11 has a diameter expanded so as to be expanded in a horizontal direction by a hydraulic cylinder 2c for clamping (see FIG. 3) in a state of being inserted into the upper end side of a steel pipe pile that is an existing pile that has been press-fitted previously. By pressing the inner wall surface of the steel pipe pile, the pile presser 10 is supported by the upper end portion of the existing pile P by grasping the upper end side of the steel pipe pile (existing pile).
In particular, the clamping device 11 takes the reaction force from the existing pile P that is held and supported, and the pile presser 10 is placed on the upper end of the existing pile P so that the pile presser 10 can press-fit a new pile. It is designed to be installed.
The clamp devices 11 are movable to the left and right or back and forth with respect to the saddle 12, except for the clamp device 11 serving as the leading reference, for example, and are aligned along a curved line such as an arc. It is possible to grip the upper ends of the plurality of piles press-fitted with the plurality of clamp devices 11, and the intervals between the piles in the pile row may be slightly different so that they can be handled.

  As shown in FIG. 1, the pile press-in machine 10 includes a front-side clamp device 11 f that is disposed closest to the chuck device 15, a rear-side clamp device 11 b that is disposed farthest from the chuck device 15, Three clamping devices 11 including a central clamping device 11c that is disposed between the clamping device 11f and the clamping device 11b are provided.

  As shown in FIGS. 2 (a) and 2 (b), the rear clamping device 11b expands the diameter relative to the support portion 1 supported by the saddle 12 and the inner wall surface of the steel pipe pile that is the existing pile P. The gripping part 2 that grips and supports the steel pipe pile, and the gripping part 2 in a state of gripping a predetermined existing pile P are moved in a direction in which they are in contact with and separated from the pile presser 10 (saddle 12). And a loading hydraulic cylinder 3 which is a loading mechanism portion that applies a load to a predetermined existing pile P to be supported.

A base portion of the loading hydraulic cylinder 3 is fixed to the support portion 1.
The clamping device 11b is provided with a pair of left and right loading hydraulic cylinders 3.

The grip portion 2 includes a fixed portion 2a connected to the support portion 1 via a loading hydraulic cylinder 3, a movable portion 2b that contacts and separates from the fixed portion 2a, and a clamping hydraulic cylinder 2c that moves the movable portion 2b. And. Note that the gripping portion 2 in the clamp device 11b is provided with a total of six clamping hydraulic cylinders 2c on the left and right sides of the loading hydraulic cylinder 3, respectively. In addition, on the upper portion of the grip portion 2, a flange portion 2 e that comes into contact with the upper end surface of the existing pile P is formed.
The clamping hydraulic cylinder 2c pushes and extends the rod portion 2d in the front-rear direction, so that the movable portion 2b is pushed out from the fixed portion 2a as shown in FIGS. Thus, the grip portion 2 grips and supports the upper end side of the existing pile P.

  The loading hydraulic cylinder 3 moves the gripping portion 2 away from the pile presser 10 (saddle 12) as shown in FIGS. 4 (a) and 4 (b) by extending the rod portion 3a in the vertical direction. Thus, it functions as a loading mechanism section that presses a predetermined existing pile P gripped by the gripping section 2.

  The front side clamping device 11f and the central side clamping device 11c are configured not to include the loading hydraulic cylinder 3 in the rear side clamping device 11b, and each gripping portion 2 of the clamping devices 11f and 11c is provided with the existing pile P. It grips and supports the upper end side.

The slide base 13 moves forward with respect to the saddle 12 and moves the chuck device 15 horizontally to the front side, so that the tip of the existing pile P supported by the leading clamp device 11 is moved without moving the saddle 12. In addition, it is possible to press-fit two piles side by side in the front-rear direction.
The leader mast 14 can be turned to the left and right with respect to the slide base 13 so that the direction of the rows of piles to be press-fitted in sequence can be bent at a right angle or bent. .
The slide base 13 and the leader mast 14 allow the chuck device 15 to move in the horizontal direction with respect to the saddle 12 provided with the clamp devices 11.

The chuck device 15 is in a state in which the back side thereof is fitted to the front side of the leader mast 14 so as to be movable up and down, and is driven up and down by a main hydraulic cylinder 16 connected to the leader mast 14 and the chuck device 15. ing.
Further, inside the chuck device 15, there is provided a pile gripping portion (not shown) that is actuated by driving a predetermined hydraulic cylinder and presses and grips the pile penetrated vertically from the four outer sides.
Since the lifting range of the chuck device 15 is limited, the chuck device 15 is lowered by gripping the pile and the chuck device 15 is lifted by releasing the pile. Thereby, the press-fitting of the pile is repeated for each stroke, and the pile can be press-fitted into the ground deeper than the lifting / lowering range of the chuck device 15.

  In addition, when the pile press-in machine 10 sequentially press-fits the pile, the saddle 12 including the clamp device 11 is moved with respect to the newly press-in pile, and the pile press-in machine 10 moves forward corresponding to one pile. Can do. The operation related to the movement of the pile press-in machine 10 on the pile is the same as that conventionally known and will not be described in detail here.

  Next, a simple loading test method according to the present invention, which is a simple loading test method for a pile using the pile presser 10 will be described.

  First, as shown in FIG. 1, while supporting the upper end side of the existing pile P press-fitted into the ground G with the clamp devices 11f, 11c, 11b, the reaction force is taken from the existing pile P, When the press-fitting machine 10 raises and lowers the chuck device 15, a new pile P <b> 1 is press-fitted into a position aligned with the existing pile P and arranged in parallel.

  In this way, by repeatedly arranging the new pile P1 in parallel with the existing pile P, the pile presser 10 sequentially connects a plurality of piles, and the predetermined existing pile P to be subjected to the loading test is clamped on the rear side. In the process supported by the device 11b, a simple loading test of the pile is executed.

And the existing pile P which the clamp apparatuses 11f and 11c support in the state which each supported the existing pile P by the front side clamp apparatus 11f, the center side clamp apparatus 11c, and the rear side clamp apparatus 11b in the pile press-in machine 10 Is used as a reaction force pile, and the loading hydraulic cylinder 3 drives the rod portion 3a to push the gripping portion 2 that grips the existing pile P that is the load test target pile in the rear clamping device 11b (FIG. 4B). The simple loading test is performed by applying a load to the existing pile P to be loaded and supported by the clamping device 11b.
Specifically, the displacement of the settlement amount measurement point when the gripping portion 2 of the clamping device 11b pushes the existing pile P to be loaded into the ground G by driving the loading hydraulic cylinder 3 with reference to the pile presser 10. A simple loading test is performed by measuring. Moreover, you may perform a simple loading test by measuring a displacement on the basis of the pile head of the existing pile P made into a fixed point.
The reaction force for pushing the existing pile P to be loaded into the ground G is the pulling resistance acting between the existing pile P and the ground G supported by the front side clamp device 11f and the center side clamp device 11c. Obtained from. When this simple loading test is performed, the front side of the clamping device 11c, which is located adjacent to the clamping device 11b that pushes the existing pile P to be loaded into the ground G, is opened. You may make it take reaction force from the existing pile P which 11f of clamping devices support. By carrying out like this, it can suppress that the existing pile P adjacent to the existing pile P which is the object of a loading test will be displaced, and can suppress the influence on the existing pile P of a loading test object.
Thus, the data required for the evaluation of the bearing capacity of the existing pile P subject to the loading test on the ground G is obtained as the relationship between the load applied to the existing pile P and the displacement of the existing pile P.

Moreover, when applying a load to the existing pile P to be loaded and performing a simple loading test, the chuck device 15 of the pile press-in machine 10 maintains a state where the new pile P1 being pressed into the ground G is gripped. Yes.
When the chuck device 15 grips the new pile P1 that is being press-fitted into the ground G, a simple loading test can be performed in which the new pile P1 is also a reaction force pile.

  Then, after completion of the simple loading test, the rod portion 3a of the loading hydraulic cylinder 3 is pulled back to the initial state (see FIG. 4A), and the pile presser 10 presses a new pile P1 into a position aligned with the existing pile P. To continue the work.

As described above, the pile press-fitting machine 10 according to the present invention includes the loading hydraulic cylinder 3 that applies a load to the existing pile P supported by the rear side clamping device 11b, and therefore, by driving the loading hydraulic cylinder 3, A simple loading test can be performed by applying a load to the existing pile P to be loaded and supported by the rear clamping device 11b.
That is, in the process of connecting a plurality of piles using the pile presser 10, a simple load test can be performed by applying a load to the existing pile P to be loaded by the pile presser 10. After the press-fitting construction of the test has been completed, it is possible to save the trouble of installing and removing the loading test device on the pile and installing and removing the temporary test pile. A suitable simple loading test can be executed.
Therefore, it can be said that the loading test using this pile press-in machine 10 is an easier simple loading test method.

In particular, the pile presser 10 includes a plurality of (three) clamp devices 11 (11f, 11c, 11b) in which the loading hydraulic cylinder 3 is arranged on the clamp device 11b on the rear side farthest from the chuck device 15. Since the simple loading test can be executed in the clamping device 11b which is the last part, the existing pile P which has completed the loading test is not used as a reaction force pile. Specifically, with respect to the existing pile P in which the reaction force is taken and the pulling force is applied, the pressure input is loaded again in the final process at the time of construction, and the existing pile P is made to express the support force. The supporting force can be confirmed.
That is, the pile press-in machine 10 does not support the existing pile P after the simple loading test with the front side clamp device 11f or the center side clamp device 11c, and does not use the existing pile P as a reaction force pile. Since the force which raises is not made to act, the existing pile P will maintain the state after finishing a simple loading test, and the confirmed supporting force will be hold | maintained. Therefore, the effectiveness of the data regarding a simple loading test is high, and it becomes a support pile which has high reliability about the measured bearing force.
Further, the simple loading test can be executed for all the piles as the final process by the loading mechanism portion (loading hydraulic cylinder 3) arranged farthest from the chuck device 15.

(Embodiment 2)
Next, Embodiment 2 of the pile loading machine according to the present invention and a simple pile loading test method using the pile pushing machine will be described. In addition, the same code | symbol is attached | subjected to the same part as Embodiment 1, and only a different part is demonstrated.

As shown in FIG. 5, the pile presser 20 includes a plurality of clamp devices 11, a front clamp device 11 f that is arranged close to the chuck device 15, and a rear side that is arranged away from the chuck device 15. Two clamping devices 11 including a clamping device 11b are provided.
And the loading hydraulic cylinder 3 which is a loading mechanism part which applies a load to the predetermined existing pile P which the clamp apparatus 11b supports is arrange | positioned at the rear clamp apparatus 11b.

Thus, if it is the pile press-fit machine 20 provided with the two clamp apparatuses 11, the existing pile P supported by the front clamp apparatus 11f will be used as a reaction force pile, and the load which the rear clamp apparatus 11b will support. A simple loading test can be performed by applying a load to the existing pile P to be tested.
Then, in the same way as the pile presser 10 of the first embodiment, in the process of connecting a plurality of piles using this pile presser 20, the pile presser 20 applies a load to the existing pile P to be loaded and simplified. A loading test can be performed.

(Embodiment 3)
Next, Embodiment 3 of the pile loading machine according to the present invention and a simple pile loading test method using the pile pushing machine will be described. In addition, the same code | symbol is attached | subjected to the same part as Embodiment 1, and only a different part is demonstrated.

  As shown in FIG. 6, the pile press-in machine 30 includes a plurality of (for example, two) clamping devices 11, and the rear side that is opposite to the front chuck device 15 with the plurality of clamping devices 11 interposed therebetween. Is provided with a loading mechanism portion 33 for applying a load to a predetermined existing pile P.

The loading mechanism section 33 moves the loading section 33a in contact with the upper end of the existing pile P subject to the loading test, and moves the loading section 33a in the direction of contacting and separating from the pile presser 10 (saddle 12). And a loading hydraulic cylinder 3 to be pushed out.
And this loading mechanism part 33 drives the loading hydraulic cylinder 3 so that the loading part 33a may be pressed against the existing pile P connected to the rear arrangement of the existing pile P supported by the two clamping devices 11. A load can be applied to the existing pile P.

In this manner, the pile press-in machine 30 can perform a simple loading test in which a load is applied to the existing pile P located behind the two clamp devices 11. Specifically, since the pile press-in machine 30 includes the loading mechanism portion 33 that can apply a load to the existing pile P that is juxtaposed behind the existing pile P supported by the two clamping devices 11, By the operation of the loading mechanism section 33, a simple loading test can be performed by applying a load to the existing pile P to be loaded.
That is, if this pile press-in machine 30 is used, the existing pile P supported by the two clamping devices 11 is used as a reaction force pile, and the load is applied to the existing pile P to be loaded against which the loading portion 33a of the loading mechanism portion 33 abuts. A simple loading test can be performed.
And in the process of connecting a plurality of piles using this pile press-in machine 30 as in the pile press-in machine 10 of the first embodiment, the pile press-in machine 30 applies a load to the existing pile P to be loaded and is simple. A loading test can be performed.

The present invention is not limited to the above embodiment.
For example, a simple loading test may be performed by applying a load to the existing pile P by lowering the chuck device 15 in the pile press-in machines 10, 20, 30.
In this case, it is preferable to apply a load to the existing pile P with the chuck device 15 arranged rearward while the pile presser (10, 20, 30) is moved backward on the existing pile P. When the pile press-in machine (10, 20, 30) is moved backward, a known attachment capable of holding and releasing the pile head of the existing pile P is attached to the chuck device 15.

  In the above embodiment, the pile loading test has been described by taking the vertical loading test of pushing the existing pile P to be loaded into the ground G as an example, but the present invention is not limited to this, for example, The present invention may also be applied to performing a pulling loading test in which a load is applied to hold and lift the existing pile P to be loaded by the gripping portion 2.

  Moreover, in the above embodiment, although the clamp apparatus 11 was pressing the inner wall surface of a steel pipe pile, and grasped the upper end side of the steel pipe pile (existing pile), this invention is limited to this. For example, the clamp device may be configured to grip an outer surface or an upper surface of an existing pile such as a steel pipe pile and grip an upper end side of the existing pile.

  Moreover, in the above embodiment, the case where the number of the clamping devices 11 is two or three has been described as an example. However, the present invention is not limited to this. For example, the number of the clamping devices 11 includes four or more. It may be any number.

  In addition, it is needless to say that other specific detailed structures can be appropriately changed.

It is a side view which shows the pile press-fitting machine which concerns on this invention. They are a top view (a) which shows a clamp apparatus provided with a loading mechanism part, and a side view (b). It is a top view which shows the inside of a clamp apparatus provided with a loading mechanism part, Comprising: It is explanatory drawing which shows the time of diameter reduction (a) of a holding part, and the time of diameter expansion (b) of a holding part. It is a side view which shows the inside of a clamp apparatus provided with a loading mechanism part, Comprising: It is explanatory drawing which shows the initial state (a) of a loading hydraulic cylinder, and the operation state (b) of a loading hydraulic cylinder. It is a side view which shows the pile press-fitting machine of Embodiment 2. It is a side view which shows the pile press-fit machine of Embodiment 3.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Support part 2 Gripping part 2a Fixed part 2b Movable part 2c Hydraulic cylinder for clamp 3 Loading hydraulic cylinder (loading mechanism part)
DESCRIPTION OF SYMBOLS 10 Pile press machine 11b Clamp apparatus 11c Clamp apparatus 11f Clamp apparatus 15 Chuck apparatus 20 Pile press machine 30 Pile press machine 11 Clamp apparatus 33 Loading mechanism part 33a Loading part P Existing pile P1 Pile G Ground

Claims (6)

The reaction force is taken from the existing pile by a plurality of clamping devices that support the upper end side of the existing pile press-fitted or rotationally pressed into the ground, and the pile is lined up by gripping and lowering the pile with a liftable lift chuck device In the process of connecting multiple piles, using a pile presser that press-fits or piles new piles in position,
With respect to the existing pile on which the reaction force has been taken and the pulling force has been applied, a pressure input is again loaded by the pile presser in the final step of construction, and a supporting force is developed in the existing pile, A simple loading test method characterized by confirming a supporting force. The reaction force is taken from the existing pile by a plurality of clamping devices that support the upper end side of the existing pile press-fitted or rotationally pressed into the ground, and the pile is lined up by gripping and lowering the pile with a liftable lift chuck device In the process of connecting multiple piles, using a pile presser that press-fits or piles new piles in position,
A simple loading test method in which a load is applied to a predetermined existing pile supported by a clamping device provided in a clamping device arranged farthest from the chuck device among the plurality of clamping devices. The reaction force is taken from the existing pile by a plurality of clamping devices that support the upper end side of the existing pile press-fitted or rotationally pressed into the ground, and the pile is lined up by gripping and lowering the pile with a liftable lift chuck device In the process of connecting multiple piles, using a pile presser that press-fits or piles new piles in position,
A simple loading test method characterized in that a load is applied to a predetermined existing pile by a loading mechanism portion provided in an arrangement on the opposite side of the chuck device across the plurality of clamping devices.   The plurality of clamping devices support the existing piles, and the chuck device grips a new pile that is press-fitted or rotationally pressed into the ground, and applies a load to the predetermined existing pile by the load mechanism described above, and loads The simple loading test method according to claim 2 or 3, wherein a test is performed.   5. The loading test is performed by applying a load by the load mechanism unit described above to all existing piles press-fitted or rotationally press-fitted by the pile press-fitting machine. Simple loading test method. The reaction force is taken from the existing pile by a plurality of clamping devices that support the upper end side of the existing pile press-fitted or rotationally pressed into the ground, and the pile is lined up by gripping and lowering the pile with a liftable lift chuck device In the process of connecting multiple piles, using a pile presser that press-fits or piles new piles in position,
A simple loading test method, wherein a loading test is performed by applying a load to the existing pile by the chuck device.

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