JPH0464403B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] Industrial Application Field The present invention relates to a device for measuring the amount of penetration of a driven pile and a proof stress calculation system using this measuring device.

Conventional technology Conventionally, the amount of penetration of a driven pile was measured by attaching a measuring paper to the side of the pile when the pile almost reached the support layer, and then manually holding a pencil placed on a pedestal as a reference. I held it and recorded it on the above paper.

Then, based on the records on the measurement paper, the amount of penetration and the amount of rebound were written down as numbers on the recording paper, and the yield strength and the like were calculated as appropriate using a calculator or the like.

Problems to be Solved by the Invention However, the above conventional method has the following problems.

(1) One person is required for each hammer pile to hold a pencil and record.

(2) Recording accuracy is poor due to individual differences depending on the person performing the measurement.

(3) Recording must be done under the falling ram, which is dirty and dangerous.

(4) The strength of the pile cannot be confirmed during hammering.

(5) Just check the strength just before the end of the stroke, so
The penetration resistance of the intermediate strata during the impact cannot be determined.

The present invention was made to eliminate the above-mentioned conventional drawbacks, and has the following objects.

(a) To relieve the person performing the measurement from hazardous work in a poor environment.

(b) When it is confirmed that each driven pile has insufficient bearing capacity, it should be possible to quickly decide whether to add more piles or perform reinforcement work.

(c) To prevent damage to the antibody due to excessive impact energy.

(d) Constantly check the penetration resistance over the entire length of the driven pile,
To make it possible to evaluate this resistance force as a frictional force.

(e) To make data useful as design materials by accumulating data on various types of soil.

(f) Work should be done remotely so that multiple piles can be managed at the same time.

[Structure of the Invention] Means for Solving the Problems The device for measuring the penetration amount of a driven pile of the present invention is installed on the side of a driven pile that is driven into the ground by dropping a hammer onto the head, and is installed horizontally. a following drum that rotates in both forward and reverse directions around a rotating shaft oriented in the direction of the driven pile, and has a non-slip means on its surface; a pressing means that elastically presses the following drum against the side surface of the driven pile; Output means for extracting the rotational direction and amount of rotation of the follower drum, which rotates in the forward direction with the driving movement of the driven pile and rotates in the opposite direction with the rebound movement of the driven pile, as an electrical signal; The strength calculation system using this measuring device is installed on the side of a driven pile that is driven into the ground by a hammer falling on the head, and is oriented in the horizontal direction. a following drum that rotates in both forward and reverse directions around a rotating shaft and having a non-slip means on its surface; a pressing means for elastically pressing the following drum against a side surface of the driven pile; an output means for extracting as an electrical signal the rotational direction and amount of rotation of the follower drum which rotates in a forward direction with the driving movement of the driven pile and rotates in the opposite direction with the rebound movement of the driven pile; rotation of the follower drum; The electric signals of the direction and amount of rotation are input as digital signals, the amount of penetration and the amount of rebound are calculated, and the driving pile is determined based on the relationship between the impact energy, which is pre-calculated from the weight of the hammer and the falling distance, and the amount of penetration. The device is characterized in that it is comprised of: an arithmetic device that calculates the proof strength of the device; and;

Embodiment Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, reference numeral 1 denotes the penetration measuring instrument body, which is fixed onto the ground G in a manner that is not affected by ground vibrations caused by pile driving.
The measuring device main body 1 may be fixed to a pile driving device main body 12. A substrate 2 is pivotally attached to the measuring instrument main body 1, and is configured to rotate around a support shaft 3 oriented in the horizontal direction. The substrate 2 may be attached to the side of the measuring instrument main body 1 so as to be slidable in a substantially horizontal direction.

A follower drum 4 is rotatably attached to the tip of the substrate 2. The axis of rotation of the follower drum 4 is oriented horizontally. Rubber such as neoprene is pasted on the outer peripheral surface of the following drum 4 as a non-slip means.

Reference numeral 5 denotes a tension spring as a pressing means, which elastically presses the following drum 4 against the side surface of the pile P.

6 is an encoder, and the following drum 4
The drum 4 is connected either directly or through an appropriate transmission means as shown in the figure, and rotates in response to the rotational movement of the follower drum 4, and generates a pulse signal such that the amount of rotation is proportional to the number of pulses. It's getting old.

The following drum 4 rotates in the forward direction as the pile P is driven, and rotates in the opposite direction as the pile P rebounds. Therefore, the pulse signal includes not only data on the amount of rotation of the following drum 4, but also data on the following drum 4, for example, by setting the driving direction of the pile P to + (positive) and setting the rebound direction to - (negative). Information on the forward and reverse rotation directions can also be transmitted.

The pulse signal from the encoder 6 is
As shown in the figure, it is amplified by amplifier 7 and A/D
A converter 8 converts the analog data into digital data. Note that the amplifier 7, A/D converter 8, etc. may not always be necessary depending on the nature of the pulse signal.

A personal computer 9 calculates the amount of penetration of the pile P from the number of pulses, and determines behavior such as penetration or rebound from the phase difference of the pulses. Furthermore, the resistance force (yield strength) of the ground is calculated from the impact energy of the hydraulic hammer 10 and the amount of penetration of the pile P. The above-mentioned impact energy is the above-mentioned hammer 1
It is solved in advance by the weight of 0 and the falling distance.

In addition, highly accurate design data can be obtained by inputting into the personal computer 9 data such as geological conditions that have been investigated in advance by boring, test piles, etc., and comparing it with the above-mentioned ground bearing capacity.

Reference numeral 11 is a plotter, which plots and processes the resistance force of the ground in the direction of the driving depth.

In addition, 12 in the figure is the main body of the pile driver.

Although the pile driving in this embodiment is carried out on the ground as shown in Fig. 2, the present invention is not limited to this, and can be carried out from a barge on the sea, on a lake or river. In this case, while simultaneously measuring data such as the tide level and water depth that change from moment to moment, these data are also used to calculate the amount of penetration of the pile P, etc.

[Effects of the Invention] (1) The tracking drum can reliably follow the penetration and rebound behavior of the driven pile, and the penetration amount and rebound amount can be extracted as accurate electrical signals.

(2) The bearing capacity of driven piles can be calculated accurately and quickly, and the bearing capacity and penetration resistance of piles that are being hammered can be immediately checked.

(3) High safety and labor saving.

[Brief explanation of the drawing]

FIG. 1 is a side view showing an embodiment of the penetration measuring device of the present invention, and FIG. 2 is an overall explanatory diagram showing the measurement calculation system. 1... Measuring instrument body, 2... Board, 3... Support shaft, 4... Following drum, 5... Tension spring, 6... Encoder, 7
...Amplifier, 8...A/D converter, 9...Personal computer, 10...Hydraulic hammer, 11...Plotter, 12...Pile driver main body, P...Pile.

Claims (1)

[Claims] 1. A hammer is installed on the side of a driven pile that is driven into the ground by falling onto the head, and rotates in both forward and reverse directions around a rotating shaft oriented in the horizontal direction. a follow-up drum provided with anti-slip means; a pressing means for elastically pressing the follow-up drum against the side surface of the driven pile; Output means for extracting the rotational direction and rotation amount of the follower drum, which rotates in the opposite direction with the rebound movement of the pile, as an electrical signal;
A device for measuring the amount of penetration of a driven pile, comprising: 2. It is installed on the side of a driven pile that is driven into the ground by a hammer falling on its head, rotates in both forward and reverse directions around a rotating shaft oriented in the horizontal direction, and has anti-slip means applied to the surface. a following drum; a pressing means for elastically pressing the following drum against the side surface of the driven pile; output means for extracting the rotational direction and amount of rotation of the follower drum which rotates in the opposite direction as an electric signal;
The electrical signals of the rotation direction and rotation amount of the follower drum are input as digital signals to calculate the penetration amount and rebound amount, and the impact energy calculated in advance from the weight and falling distance of the hammer and the above penetration amount are calculated. 1. A resistance calculation system using a driving pile penetration measuring device, characterized in that it is comprised of: a calculation device for calculating the resistance of a driven pile from a relationship; and;