JP2698842B2 - Loading test equipment for rotary press-fitting piles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring the strength of a rotary press-fitting pile in civil engineering foundation work, and more particularly to an apparatus for performing a load test on site.

[0002]

2. Description of the Related Art Heretofore, the strength of a pile that has been rotationally press-fitted has been obtained by calculation from the structure, geology, etc. of the pile, and there is no means for actually measuring the strength of the pile. However, at the site, the yield strength is not always as calculated, and the actual yield strength had to be obtained directly by a load test.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide an apparatus for directly measuring the proof stress of a rotary press-fitted pile at a site of civil engineering foundation work.

[0004]

Means and embodiments of the present invention are as follows. <Means> (a) A hydraulic jack with a piston rod extending and contracting in the vertical direction is provided on the lower surface of the lid, and an outer guide for guiding the pile is provided on the outer periphery of the lower part. A loading unit which is attached and comprises a pressure plate for applying a load from the hydraulic jack to a pile, and is used by being attached to the tip of a crane arm; (b) a hydraulic unit for supplying oil to the hydraulic jack via a hydraulic hose; A pressure transmitter that is provided on the hose and converts the oil pressure in the hose into an electric signal;
And an operation unit including a recorder for recording a load applied to the pile by a signal from the transmitter.

<Embodiment> (a) A pressurized cylinder which is provided with a hydraulic jack whose piston rod expands and contracts in the vertical direction on the lower surface of a lid and an outer guide for guiding a pile is provided on the outer periphery of a lower part, and is a downwardly opened pressurized cylinder. A loading section attached to the upper end of the pile, which is composed of a pressure plate for applying the load from the hydraulic jack to the pile, and used by being attached to the reduction gear provided at the tip of the arm of the crane. (B) The hydraulic jack is connected to the hydraulic jack via a hydraulic hose. A hydraulic unit that supplies oil, a pressure transmitter that is provided on the hydraulic hose and converts the hydraulic pressure in the hose into an electric signal,
An operation unit comprising a recorder for recording a load applied to the pile by a signal from the transmitter, the operation unit being provided in a control unit of the crane.

[0006]

When oil is supplied from the hydraulic unit of the operation unit to the hydraulic jack of the loading unit, the hydraulic jack loads the pile via the pressurizing plate attached to the upper end of the pile. The load applied to the stake is detected from the pressure of the oil supplied to the jack, and this pressure is converted into an electric signal by a pressure transmitter provided on a hydraulic hose and output to a recorder.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An apparatus according to the present invention will be described below in detail with reference to FIGS. FIG. 1 shows the configuration of an apparatus according to the present invention. In the figure, reference numeral 1 denotes an operation unit for outputting control and data of the entire apparatus, and 2 denotes a loading unit for applying a load to a steel pipe pile.

The operation unit 1 comprises a hydraulic unit 4 connected to an operation panel 3 and a recorder 5 for recording the load on the loading unit 2. The hydraulic unit 4 includes a pressure side hydraulic hose 6a and a return side hydraulic pressure. It is connected to the hydraulic jack 7 of the loading section 2 via a hose 6b.

The recorder 5 is connected to a pressure transmitter 8 provided on the pressurizing-side hydraulic hose 6a via a signal cable 9, so that the hydraulic pressure of the pressurizing-side hydraulic hose 6a is continuously output on recording paper. I have.

FIGS. 2 and 3 show the loading section 2. The loading section is a pressurized cylinder 10 having a closed cylindrical shape, a hydraulic jack 7 provided on the lower surface of a lid 10a of the pressurized cylinder, and a pressurized cylinder. Outer guides 11 are provided on the outer periphery so that the lower ends thereof protrude.

At the center of the upper surface of the lid 10a of the pressurizing cylinder 10, there is formed a connection projection 12 having a non-circular planar shape that fits into a socket of a reduction gear 13 attached to the tip of an arm of a crane truck described later. In addition, a hydraulic hose 6 connecting the hydraulic jack 7 in the pressurizing cylinder and the hydraulic unit 4 of the operation unit 1 is passed through the center of the connection projection 12. Since the pressurizing cylinder is rotated by the reduction gear when the steel pipe pile 14 is press-fitted, the hydraulic hoses inside and outside the pressurizing cylinder are connected by a rotary swivel joint 15 so that the hydraulic hose 6 is not twisted.

The load from the hydraulic jack 7 is applied to the upper end of the steel pipe pile 14 via the pressure plate 16, and the pressure plate extends along the inside of an outer guide provided on the outer periphery of the pressure cylinder 10. It can slide up and down.
Reference numeral 17 in the figure denotes an inner guide for guiding the pressurizing plate 16 to the steel pipe pile 14.

The apparatus of the present invention configured as described above has
Use as follows: FIG. 4 shows a use state of the apparatus. The operation unit 1 includes an operation panel 3 and a recorder 5 provided on a crane cockpit 18a of a crane truck 18, a hydraulic unit 4 provided on a carrier 18b, and a loading unit 2 provided on a crane vehicle. 18 arms 19
It is attached to a reduction gear 13 provided at the tip.

The loading section is attached to the upper end of the pile before press-fitting the pile. The pressing plate 16 is placed on the upper end of the pile, and the pressing cylinder 1
Pieces 14a and 1 welded to the outer periphery of the upper end of the pile with 0
The outer guides 11, 11 are fitted between 4a.

When the pile is pressed in, the arm 19 of the crane truck 18 is tilted downward to apply a load to the pile, and the reduction gear 1
3 is driven to press the pile 14 into the ground. At this time, the rotation of the reduction gear 13 causes the outer guides 11
Hooks the pieces 14a, 14a at the upper end of the pile to rotate the pile.

When the press-fitting of the pile is completed, the rotation of the reduction gear 13 is stopped, and the hydraulic unit 4 is operated while holding the loading portion 2 by the arm 19 of the crane truck 18 so that the piston rod 7a of the hydraulic jack 7 of the loading portion 2 is moved. The pile is extended and a load is applied to the pile via the pressure plate 16.

At this time, the load applied to the pile from the hydraulic jack is detected as a hydraulic pressure by the pressure transmitter 8 provided on the hydraulic hose 6a on the pressurizing side, converted into an electric signal and sent to the recorder 5, and is recorded on the recording paper. Is output continuously.

Reference numeral 20 in the figure denotes a hook of a crane truck, which is used when the pile 14 is erected.

FIG. 5 shows an example of data output from the recorder 5. A load F at a point P at which the load from the hydraulic jack becomes constant is obtained as the proof stress of the steel pipe pile.

Although the recorder in the above embodiment merely outputs load data to recording paper, the recorder is constituted by a microcomputer or the like, and the load data is stored in the recording paper.
The data may be output to an RT screen or converted into magnetic data and recorded. The recorder and the operation panel may be constituted by a microcomputer or the like, and the hydraulic unit may be automatically controlled based on the load data sent from the pressure transmitter. You may do so.

[0021]

Since the device of the present invention has the above-described structure, the following effects can be obtained. Since the load applied by the hydraulic jack to the upper end of the pile after rotary press-fitting is detected from the oil pressure of the oil supplied to the hydraulic jack, accurate load data can be obtained on the operation unit side.

Further, since the loading portion can be used while being mounted on the crane even when the pile is rotated and press-fitted, the test can be easily performed without the trouble of mounting and dismounting.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an apparatus according to the present invention.

FIG. 2 is a plan view showing a loading unit.

FIG. 3 is a longitudinal sectional view of a loading section.

FIG. 4 is a diagram showing a use state of the device according to the present invention.

FIG. 5 is a graph showing an example of output data of the device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Operation part 2 Loading part 3 Operation panel 4 Hydraulic unit 5 Recorder 6 Hydraulic hose 7 Hydraulic jack 8 Pressure transmitter 10 Pressure cylinder 11 Outer guide 12 Connection projection 13 Reduction gear 14 Steel pipe pile 15 Swivel joint 16 Pressure board 17 Inner guide 18 Crane truck 19 Arm

Claims (1)

(57) [Claims] (1) A pressure cylinder having a hydraulic jack whose piston rod expands and contracts in the vertical direction is provided on a lower surface of a lid portion, and an outer guide for guiding a pile is provided on a lower outer periphery with a lid, and a pressurizing cylinder which opens downward is provided. A loading unit attached to the upper end, comprising a pressure plate for applying a load from the hydraulic jack to the pile, and used by being attached to the tip of a crane arm. (B) A hydraulic unit that supplies oil to the hydraulic jack via a hydraulic hose. A pressure transmitter provided on a hydraulic hose and converting a hydraulic pressure in the hose into an electric signal;
An operation unit comprising a recorder for recording a load applied to the pile by a signal from the transmitter.