JPS604326B2 - Pile bearing capacity determination device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a foundation pile capable of quickly and reliably determining the relationship between the constructed pile and the supporting layer in order to construct the foundation pile on the optimum ground in an ideal condition. The present invention relates to a supporting force determination device.

Normally, when constructing a supporting ground for a foundation pile using an earth auger or the like without noise or vibration, in order to obtain a reliable supporting capacity of the foundation pile, the conditions for inserting the foundation pile into the supporting ground and driving approach conditions are required. etc. must be accurately measured for each driven pile.

Conventionally, this has been done using completely primitive measurement methods, such as drilling tables that can be measured in advance and determining the properties of the earth and sand that has been discharged to the ground. Not only is it difficult to calculate and determine, but it is especially impossible to measure the bearing capacity of each individual pile body. Recently, a method has also been developed in which a load sensing device is installed on a part of the pile or auger to measure the relationship between the pile and the supporting ground based on changes in load during driving. The measurement method uses the load sensing device to measure and record only the changes in the current caused by the rotary borehole, so even if changes in the load current due to the hardness of the ground can be detected, the penetration speed of the foundation pile, There was a serious drawback in that there was no correlated energy record such as displacement, and therefore it was impossible to accurately know the bearing capacity, embedment, etc. of the foundation pile.

In particular, the output (W) of the driving part of a pile driver, that is, the amount of work done when driving a pile pillar, is proportional to the product of voltage, current, and power factor, and the output and current are not proportional to each other. Measuring and recording the output load during pile driving based only on changes in current load is inaccurate and unsatisfactory. The present invention has been developed based on the results of various experimental studies in view of such circumstances. N
), and furthermore, it is noted that the ground hardness (N) is expressed as a function of the energy (E), displacement (X), and velocity (V') required for the rotational penetration of the foundation pile and earth auger into the ground. We decided to request the recorded measurements described below.

That is, the present invention simultaneously measures and records, on a sheet of recording paper, the energy required for the rotational penetration of the pile and the earth auger, the displacement, and, if necessary, the speed detected by the displacement. It is an object of the present invention to provide a pile support force determination device that can quickly and accurately determine the support state.

The embodiments of the present invention will be explained in detail below based on illustrative drawings.
is a pile driver, 2 is a drive unit, 3 is an auger, 4 is a wire 5
This is a displacement meter that detects vertical displacement of a pile pillar connected to a part of the disturbance section 2 while maintaining a constant tension. A power load sensing part 6 for sensing load power is provided in a part of the drive unit 2 and connected to a recorder 7 through suitable wiring. In addition, the displacement meter 4 is connected to several tension pulleys 8 as shown in the second figure, for example.
, 8', 8'', a pulse oscillator 9, a winding drum 10, and a torque motor 11.
A constant load is applied to the pulley by winding the wire 15 through the chain belt 12 so that the wire 5 is in tension.
In addition, a chain belt 13 is stretched between some of the tension pulleys 8' and the pulse oscillator 9, and the movement of the wire 5 that can be read by the tension pulley 8'', that is, the vertical movement of the drive unit 2, is electrically transmitted by the pulse oscillator 9. This electrical signal is then transmitted to the recorder 7 to be recorded. The speed can be recorded on the recording paper 7' of the recorder 7 at the same time as the power load.

For example, the speed can be recorded directly on the surface of the recording paper, or it can also be detected and recorded based on the relationship between the displacement and the time expressed by the amount of feed of the recording paper. The sending calendar of the present invention has the above-mentioned configuration, and its operating state will be explained next. First, a pile post P is suspended below the drive section 2 with the auger 3 as the axis, and the drive section 2 When applying current to the auger 3, the auger 3 rotates to drill a hole in the ground, and the pile post P is lowered into the hole. An instruction is sent to the recorder 7 via the power load sensing portion 6 to record the information. At the same time as the recording, the displacement measured and detected by the displacement meter 4 operated via the wire 15 and, if necessary, the speed detected by the displacement are recorded on the surface of the recording paper 7' together with the electric power load. be done. As described above, the device of the present invention measures the rotational penetration energy that changes due to various strong and weak load resistances that occur due to changes in the strata at the tip of the auger 3, using the drive unit 2 and the tip of the auger 3 driven by this. Since the obtained displacement and, if necessary, the penetration velocity detected by the displacement are recorded at the same time, the energy E, displacement x, and if necessary velocity V are recorded for each depth of penetration of the pile and auger, as shown in Figure 3. By clearly recording the functional state of the pile, the pile construction status can be immediately known with certainty, and based on this, a strong foundation ground can be created.

In particular, in the present invention, the load resistance of the drive section 2 is
Since the energy itself is detected and recorded, the ground resistance during pile driving, that is, the hardness of the pile supporting ground and the penetration situation can be grasped very accurately based on the change in energy, and the bearing capacity can be easily and reliably determined. It is.

[Brief explanation of drawings]

The drawings illustrate an embodiment of the pile bearing capacity determination device according to the present invention, FIG. 1 is a schematic diagram of the entire device, FIG. 2 is a structural diagram of the main parts of the device, and FIG. 3 is a record showing the pile progress state. It's paper. Explanation of symbols, 1...Pile driver, 2...Drive unit, 3...Auger, 4...Displacement meter, 5...Wire 1, 6...Power load sensing part, 7...Recorder, 7 '...recording paper, 8,8',
8″…Tension pulley, 9…Pulse oscillator, 10
... Winding drum, 11... Torque motor, 12... Chain belt, 13... Same as above, P... Pile pillar. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1. A power load sensing device is installed in a part of the drive unit of the pile driver to measure the power load during pile driving and guide it to a recorder and record it.
In addition, a displacement meter that detects the vertical displacement of the pile column is connected to the drive unit via a wire, and the displacement meter is connected to the drive unit via a wire.
The state of displacement during pile driving detected by this is transformed into an electrical signal, transmitted to a recorder, and connected to a recorder for recording, and the recorder simultaneously records the electric power load and displacement of the pile pillar. A pile bearing capacity determination device characterized in that it is provided so as to.