JPS6344890B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for measuring the bearing capacity of a driven pile during pile driving work.

Conventionally, in so-called loading tests to measure the bearing capacity of driven piles, a steel weight (called a Monken) was placed at a height of approximately 1 m to 5 m on the head of the pile to be measured. The most commonly used method was to drop a pile from the ground, measure the amount of sinkage of the pile, and calculate the bearing capacity of the pile.

However, in the above-mentioned conventional method, since the weight is dropped, the vibrations and impact noises at that time reverberate around the work area, causing vibration and noise pollution, resulting in a poor work environment.

In view of the above-mentioned conventional drawbacks, an object of the present invention is to
By applying pressure to the pile using a measuring pressure means and applying it as a weight load from a pile driving machine,
It is an object of the present invention to provide a method and apparatus for measuring the bearing capacity of a pile, which can quickly and accurately perform the measurement, and can almost completely eliminate vibration and noise.

Hereinafter, illustrated embodiments embodying the present invention will be described in detail.

First, to explain the equipment used in the measurement method of this example, in the figure, 1 indicates a well-known pile driving machine that can run, and the upper part of the main frame, which has endless tracks etc. on both sides, has a driver's seat and a driving device. A swing main body 2 is equipped with various power system devices such as the following, and a leader 4 is installed at the front of the swing main body 2 via a bracket 3 so as to be able to be raised and lowered (the figure shows an upright state). ing. A rotary pile driving mechanism (excavation mechanism) 5 such as an auger is installed on the front side of the leader 4 so as to be movable up and down via a wire 6 disposed on the leader 4. This pile driving mechanism 5 is equipped with a fixing means (not shown) so that it can be fixed at a predetermined lower part of the leader 4. The leader 4 is raised and lowered by a backstay 7 that can be expanded and contracted, and is configured to be stable when standing up and when tilting.

A measurement pressure means 8 is installed at the bottom of the pile driving mechanism 5, and the measurement pressure means 8 is composed of a hydraulic cylinder 9, as shown in FIGS. 2 and 3. A mounting cylinder 11 that can be attached to and removed from the lower flange 5a of the pile driving mechanism 5 is screwed to the end (upper end) of the rod 10, and a mounting tube 11 that is attached to and detached from the lower flange 5a of the pile driving mechanism 5 is screwed to the end (lower end) of the cylinder 12, which is attached to the pile head of the pile driven. A flange-like mounting portion 14 is formed to removably attach a cap-shaped cap 13 formed in a corresponding manner so as to be fitted thereinto, and a plurality of mounting holes 14a are formed through the mounting portion 14. The mounting cylinder 11 has a flange 11b formed at its upper end with a plurality of mounting holes 11a penetrating therethrough, and a hexagonal inner hole at the substantially lower part is connected to the cylinder 12.
The two locking rods 15 are removably inserted into the outer periphery of the hexagonal upper end of the hexagonal upper end so as to engage both of the fitting portions in the fitted state. Thus, the mounting tube 11 is fastened to the flange 5a of the pile driving mechanism 5 by bolts B etc. through the mounting hole 11a, and the locking rod 1
When the locking rod 15 is in the locked state, the rotation caused by the excavation work of the pile driving mechanism 5 is transmitted to the entire hydraulic cylinder 9 without transmitting it to the rod 10. This allows the rod 10 to freely expand and contract with respect to the cylinder 12, and when the cap 13 is attached to the attachment portion 14 of the cylinder 12, the attachment hole 14a is used.
This is done using a bolt B or the like via the holder. However, in order to cope with normal excavation work, a screw (not shown) for excavation can be attached to the attachment part 14 with a bolt or the like through the attachment hole 14a.

The hydraulic circuit in the hydraulic cylinder 9 is as shown in FIG.
6, the three-way switching control valve 17, the rod side pipe 18, and acting on the rod side of the hydraulic cylinder 9 to retract the rod 10. It is configured to act on the head side of the hydraulic cylinder 9 through a pipe 19 and move in the direction of extending the rod 10 via the piston, and a pipe 20 branched from the head side pipe 19 is supplied with operating pressure. A digital pressure gauge 21 and an output meter 22 to display, and a recorder 23 to convert the working pressure into the supporting capacity of the pile to be measured and record it.
is installed as a measuring device.

Next, the function of the above-mentioned apparatus and the measuring method of this example will be described.

Now, in the state where the pile T is driven by the pile driving mechanism 5 of the pile driving machine 1, the pile driving mechanism 5 is fixed to the lower part of the leader 4 by the fixing means, and the dimensions of the pile are adjusted. After attaching the matched cap 13 to the attachment part 14 of the measuring pressurizing means 8 using bolts B, etc., the locking state between the cylinder 12 and the mounting tube 11 is released by removing the locking rods 15, 15. do. In this case, the entire pile driving machine 1 is moved in advance so that the centers of the pile head of the pile to be measured and the cap 13 are aligned.

Then, the hydraulic cylinder 9 of the measurement pressurizing means 8 is extended and the cap 13 is placed on the head of the pile T. That is, when pressure oil is applied to the head side of the hydraulic cylinder 9, the cylinder 12 and rod 10
The rods 10 move relative to each other, and the rod 10 is extended, and the cap 13 on the cylinder 12 side is placed on the head of the pile T. Thereafter, when the above-mentioned working oil pressure is gradually increased, the measurement pressure means 8 operates in a stretched state between the pile T and the pile driving mechanism 5 on which the weight of the pile driving machine 1 acts. Then, the weight of the pile driving machine 1 is added to the measurement pressure means 8, and eventually the pile T sinks further or the pile driving machine 1, that is, its pile driving mechanism 5 side receives a reaction force and floats up. It becomes a state of ivy. By reading the pressure of the hydraulic pressure in this state, the supporting force of the pile T to be measured is measured.

That is, by applying a working hydraulic pressure corresponding to the supporting force of the pile T to be measured to the measurement pressure means on which the weight of the pile driving machine 1 acts, if the pile T does not sink under that pressure ( If the pile driving machine 1 lifts up), it can be measured and determined that the pile T has been driven with more than the desired bearing capacity, and the pressure at that time is sequentially recorded on the recorder 23. . Additionally, if the pile T is found to be sinking, it can be determined and determined that the pile T has not been driven with the desired bearing capacity; however, in this case, the pile T will sink further. The state will be the same as when it was typed in, and it will function as a correction.

In the manner described above, the bearing capacity of the pile T that has been driven is measured.

In addition, in this embodiment, for normal excavation work, the rod 10 of the measurement pressure means 8 is retracted to fit the mounting tube 11 into the cylinder 12, contrary to the above, and in the fitted state. By inserting the locking rods 15, 15, the two can be locked, and this can be done without any problem by replacing the cap 13 with an ordinary screw (not shown). In this case, the means for fixing the pile driving mechanism 5 to the leader 4 is released.

Next, another example of the apparatus of the present invention will be explained with reference to FIGS. In the lower space of the main frame 1a, the measuring pressurizing means 8 is composed of four hydraulic cylinders 9a to 9d, and each rod 10 of the hydraulic cylinders 9a to 9d is installed.
The upper ends of the cylinders a to 10d are mounted to the lower frame 1b of the main frame 1a via a bracket 30, and the lower ends of each cylinder 12a to 12d are also connected to each other by a bracket 31. The center is aligned with the center of gravity of the pile driving machine 1, and a cap 13 that matches the head of the pile T to be piled is removably fastened to the lower surface of the center, and the rest of the structure is the same as the previous example. It is similar to

Therefore, the measurement method in this example is a measurement method in which four hydraulic cylinders are operated simultaneously so that the entire weight of the pile driving machine 1 acts on the measurement pressurizing means 8. , the others are the same as above.

In addition, in this embodiment, the number of hydraulic cylinders 9 may be one as in the previous example.

Furthermore, in the two embodiments described above, if the weight of the pile driving machine 1 is less than the supporting capacity of the pile to be measured, it is possible to attach another weight.

Further, in the above-described embodiment, the mounting tube 11 on the rod side of the hydraulic cylinder 9 and the cylinder 12 are locked by the locking rod 15, but other means may be used.

As described above, in the present invention, after driving a pile using the pile driving mechanism installed in a pile driving machine, the pressure means for measurement installed in the machine is applied onto the pile to be measured. This method differs from conventional methods in that the bearing capacity is measured by placing the pile on the pile and applying the pressure from the measuring pressurizing means and the weight of the pile driving machine as a load to the pile. It has the advantage of being extremely simple, quick and safe, and accurate without generating vibration or noise.

In the case of the device, a pressure means for measurement consisting of a hydraulic cylinder or the like is installed at the bottom of the pile driving mechanism, which is installed on the leader of the pile driving machine so as to be able to move up and down. The structure is extremely simple because it has a mounting part for attaching and detaching a cap that matches the head of the pile to be measured.

In addition, a measurement pressure means consisting of one or more hydraulic cylinders is installed at the bottom of the main frame of the pile driving machine, and the bottom of the measurement pressure means is attached to the pile cap of the pile to be measured. Since the center of the cap and the center of gravity of the pile driving machine are aligned with each other, in addition to the above-mentioned effects, the pressure means for measuring the weight of the pile driving machine can be rationally used. It has the advantage of being able to act on

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a front view schematically showing the entire device, FIG. 4 is a hydraulic circuit diagram, FIGS. 5 and 6 show another embodiment, FIG. 5 is a partially omitted plan sectional view, and FIG. 6 is a partially cutaway front view. DESCRIPTION OF SYMBOLS 1... Pile driving machine, 5... Pile driving mechanism, 8... Pressure means for measurement, 13... Cap, T... Pile.

Claims (1)

[Claims] 1. After a pile is driven by a pile driving mechanism installed in a pile driving machine, a pressure means for measurement installed in the machine is placed on the pile to be measured. With,
Measurement of the bearing capacity of a driven pile in a pile driving operation in which the pressing force by the measurement pressure means and the weight of the pile driving machine are applied as measurement loads to the pile, and the bearing capacity of the driven pile is measured. Method. 2. A measurement pressure means consisting of a hydraulic cylinder, etc. for applying pressing force to the pile is installed at the bottom of the pile driving mechanism, which is installed on the leader of the pile driving machine so as to be able to move up and down. 1. An apparatus for measuring the bearing force of a pile driving in pile driving work, characterized in that a mounting part is formed at the bottom of the pressure means to removably attach a cap that matches the head of the pile to be measured. 3. A measurement pressure means consisting of one or more hydraulic cylinders, etc. for applying pressing force to the pile is installed at the bottom of the main frame of the pile driving machine, and a measurement pressure means is installed at the bottom of the measurement pressure means. 1. A device for measuring the bearing capacity of driving piles in pile driving work, characterized in that a cap is installed that matches the head of the pile to be measured, and the center of the cap is aligned with the center of gravity of the pile driving machine.