JP3938702B2 - Rotating buried pile driving device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pile driving device for a rotary buried pile provided with a support layer confirmation device.
[0002]
[Prior art]
In general, when a building such as a house or a building is constructed, a pile is driven at a predetermined interval along a foundation shape under a concrete foundation in a place where the ground is weak. Depending on the strength of the ground, this pile must be buried in the ground until it reaches the support layer, and the length of the pile also depends on the ground strength at the construction site.
[0003]
For this reason, a geological survey is conducted in advance before construction. There are various survey methods, but the most common method is the Swedish sounding type geological survey. In this method, a rod with a triangular pyramid-shaped screw point attached to the tip is rotated while applying a constant load of, for example, 100 kg, and the rod is pushed into the ground. The ground strength in the depth direction is measured from the rotational speed.
[0004]
For example, the rod rotation speed is measured 30 times before being pushed 25 cm from the ground surface, the rod rotation speed is 25 times to push from 25 cm to 50 cm, and the rod rotation speed is 24 times to push from 50 cm to 75 cm. As the number of rotations increases, the ground strength increases. In this way, measurement is performed up to the depth reaching the N value aimed at as the support layer. This N value indicates the ground strength based on the number of hits required to penetrate the pile to the specified depth by dropping the hammer in the standard penetration test, and is obtained by converting the rotation speed measured by the Swedish sounding method. Can do.
[0005]
From the results of this geological survey, the pipe diameter and length of the pile to be buried are determined, and the pile is pushed in while being rotated by a pile driving device and buried at the construction site. However, there are several survey points by the Swedish sounding method. On the other hand, piles are buried along the foundation shape at intervals of 180 cm, for example, so that piles are driven into unexamined places. It was not possible to confirm whether the tip of the pile had reached the support layer by simply pushing it so that the head was exposed from the ground. In addition, there was a problem that it was not possible to confirm whether the piles of the length determined based on the results of the geological survey were driven accurately one by one after building the building.
[0006]
[Problems to be solved by the invention]
The present invention improves the above-mentioned problem, incorporates a mechanism similar to the Swedish sounding-type measuring device into the pile driving device, measures the strength of the ground while driving the pile, and supports one piece as far as the geological survey results. The present invention provides a pile driving device for rotating buried piles that can be confirmed whether piled one by one.
[0007]
[Means for Solving the Problems]
The pile driving device of the rotary buried pile according to claim 1 of the present invention, the pile rotation drive unit that holds and rotates the upper end of the rotary buried pile is attached to be vertically movable along the guide column that is vertically supported, In a pile driving device for a rotary embedded pile that is provided with an elevating mechanism for moving the pile rotation drive unit along the guide column and that is pushed into the ground while rotating the pile, a pressing pressure control unit that presses the rotary embedded pile at a constant pressure; , A support layer confirmation device comprising a rotation speed measurement unit for measuring the rotation speed of the pile, a settlement amount measurement unit for measuring the settlement amount of the pile, and a ground strength calculation unit for calculating the ground strength from the rotation speed with respect to the unit settlement amount Is provided.
[0008]
In the pile driving device for rotary buried piles according to claim 2 of the present invention, the drive unit for moving the pile rotation drive unit along the guide column rotates the chain hung around the guide column. The pushing pressure control unit controls the pushing pressure by measuring the pressure of the hydraulic pump that drives the hydraulic motor.
[0009]
Furthermore, the pile driving device for the rotary buried pile according to claim 3 is characterized in that the rotary buried pile is formed by press-forming the lower end of the steel pipe and a plurality of blades project radially.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail with reference to FIG. In the figure, reference numeral 1 denotes a pile driving device for a rotary buried pile. A support 4 is attached to a vehicle body 3 that runs on a crawler 2, and a guide column 6 is rotatably supported at the tip thereof via a hinge. The angle of the guide column 6 is adjusted by the cylinder 7.
[0011]
A hydraulic motor 8 is attached to the lower part of the guide column 6, and a lower sprocket 9A is connected to the output shaft. Further, an upper sprocket 9B is attached to the upper portion of the guide column 6, and a chain 10 is wound around the lower sprocket 9A. A guide rail 12 is attached to the side surface of the guide column 6, and a bracket 13 connected to the chain 10 is attached to the guide column 6 so as to be movable up and down, thereby forming an elevating mechanism 5.
[0012]
A pile rotation drive unit 14 is attached to the bracket 13. The pile rotation drive unit 14 includes a hydraulic motor 15 and a catcher 16 provided at the lower portion thereof. The catcher 16 supports and rotates the upper portion of the rotary buried pile 17. Reference numeral 18 denotes a support ring that is attached to the lower portion of the guide column 6 and rotatably supports the rotary buried pile 17.
[0013]
As shown in FIG. 2, the support layer checking device 19 includes a pushing pressure control unit 20 connected to the hydraulic pump 11 of the lifting mechanism 5, a settlement amount measuring unit 21 connected to the hydraulic motor 8 of the lifting mechanism 5, a pile. A rotation speed measurement unit 22 connected to the catcher 16 of the rotation drive unit 14, a ground strength calculation unit 23 connected to the subsidence amount measurement unit 21, and a display unit 24 such as a printer connected thereto. Has been.
[0014]
The indentation pressure control unit 20 detects the oil pressure with a pressure sensor provided in the oil discharge circuit of the hydraulic pump 11, and adjusts the oil pressure of the hydraulic pump 11 so as to obtain a constant indentation pressure determined from the diameter of the rotary buried pile 17. It comes to control. The sinking amount measuring unit 21 is a non-contact type sensor such as an electrostatic capacity sensor attached to the output shaft of the hydraulic motor 8 that rotates the chain 10 and the lower sprocket 9A, or a contact type sensor such as a limit switch. The amount of movement of the chain 10, that is, the amount of settlement of the rotary buried pile 17 is measured by detecting the amount of rotation.
[0015]
The rotational speed measuring unit 22 is a non-contact type sensor such as a capacitance sensor attached to the catcher 16 of the pile rotation driving unit 14 or a contact type sensor such as a limit switch. The number of rotations of the rotary buried pile 17 is measured by detecting the number of rotations of the catcher 16 attached to the pile.
[0016]
In addition, the ground strength calculation unit 23 uses, for example, a Swedish sounding measurement method based on the rotation speed n of the rotary buried pile 17 measured by the rotation number measurement unit 22 and the settlement amount of the rotary buried pile 17 detected by the settlement amount measurement unit 21. The rotational speed n with respect to the unit settlement amount L every 25 cm is measured, and the strength of the ground is calculated. The calculated ground strength is output to a display unit 24 such as a printer and printed out. In this case, data converted into N values may be printed out.
[0017]
In addition, as the rotating buried pile 17 to be buried, for example, as shown in FIG. 1, a trough that is inclined obliquely from the three directions of the outer periphery toward the center is formed on the tip side of the cylindrical steel pipe, and these neighboring troughs In the meantime, a blade in which three blades 25 whose front end side is closed and the rear side is sequentially swollen in the circumferential direction is radially used is used.
[0018]
Next, a method of pile driving with the pile driving device of the rotary buried pile having the above configuration will be described. The geology of the site where the building will be constructed is surveyed in advance using the Swedish sounding method. In this Swedish sounding method, the rod with a triangular pyramid screw point attached to the tip is rotated while applying a constant load of 100 kg, for example, and the rod is pushed into the ground to obtain a unit settlement of 25 cm. Measure the ground strength in the depth direction from the number of rod rotations to reach.
[0019]
Based on the results of this geological survey, the weight of the building, and the depth to reach the target N value as the support layer, the pipe diameter and length of the rotary buried pile 17 to be buried are determined and processed at the factory. Carry in. When the rotary buried pile 17 is long, a steel pipe may be added on site. At the site, the load applied to the rotary buried pile 17 having the bottom cross-sectional area D, that is, the indentation pressure P, is equal to the load per cross-sectional area d of the screw point with respect to the load 100 kg by the Swedish sounding method, 100 kg / d = P / D. Set to.
[0020]
In this way, the indentation pressure P is set to be constant by the indentation pressure control unit 20, and the rotary buried pile 17 is held by the catcher 16 and the support ring 18 and supported along the guide column 6. Thereafter, the hydraulic pump 11 of the elevating mechanism 5 and the hydraulic pump 12 of the pile rotation drive unit 14 shown in FIG. 2 are operated with the tip of the rotary buried pile 17 aligned with the buried point of the ground.
[0021]
When the hydraulic pump 11 of the elevating mechanism 5 is operated, the hydraulic motor 8 is rotated by the hydraulic pressure, the lower sprocket 9A connected to the hydraulic motor 8 is rotated, and the chain 10 hung between the upper sprocket 9B and the guide sprocket 6 Rotate inside. A bracket 13 of a pile rotation drive unit 14 is connected to the chain 10, and a hydraulic motor 15 and a catcher 16 supported thereon are lowered.
[0022]
At this time, the load applied to the rotary buried pile 17 by the catcher 16, that is, the pushing pressure P, can be made constant by controlling the discharge pressure of the hydraulic pump 11 by the pushing pressure control unit 20. Further, since the catcher 16 rotates integrally with the hydraulic motor 15 that is rotated by the hydraulic pump 12 of the pile rotation driving unit 14, the rotary buried pile 17 supported by the pile is driven into the ground while rotating at a constant pushing pressure P. It will be.
[0023]
Since the three blades 25 are projected at equal intervals on the tip of the rotary buried pile 17, the blade 25 rotates to scrape the soil and press the scraped soil against the inner wall surface of the hole. It is buried while compacting the ground. In this manner, the rotary buried piles 17 are driven at predetermined intervals along the foundation shape of the building.
[0024]
In this driving process, the output shaft of the hydraulic motor 8 that rotates the chain 10 and the non-contact type sensor such as a capacitance sensor attached to the lower sprocket 9A or the contact type sensor such as a limit switch Is detected, and the subsidence amount of the rotary buried pile 17 is measured by the subsidence amount measuring unit 21.
[0025]
At the same time, by detecting the number of rotations of the catcher 16 with a non-contact type sensor such as a capacitance sensor attached to the catcher 16 of the pile rotation drive unit 14 or a contact type sensor such as a limit switch, the rotation is buried. The rotational speed n of the pile 17 is measured by the rotational speed measuring unit 22.
[0026]
The rotation number n of the rotary buried pile 17 measured by the rotation number measuring unit 22 and the settlement amount of the rotary buried pile 17 detected by the settlement amount measuring unit 21 are calculated with respect to the unit settlement amount L every 25 cm by the ground strength calculation unit 23. The rotational speed n is measured, the ground strength is calculated, and the calculated ground strength is printed out by the printer of the display unit 24.
[0027]
By comparing the result of this printout with the result of the geological survey conducted in advance by the Swedish sounding method, it is possible to check whether the rotary buried piles 17 have reached the support layer one by one, and as driving data It can be managed and will be recorded at a later date when compensation issues arise.
[0028]
In the above embodiment, the lifting mechanism 5 has a structure in which the hydraulic motor 8 and the chain 10 are combined. However, the structure in which the rack and the pinion are combined, or a hydraulic cylinder is attached to the guide column 6 and the pile rotation driving unit 14 is mounted. The structure of raising and lowering may be used. In this case, the sinking amount measuring unit 21 may measure the expansion / contraction amount of the rod of the hydraulic cylinder. Moreover, although the case where the sensor which measures rotation speed was attached to the catcher 16 of the rotation drive part 14 was shown, the structure attached to the output shaft of the hydraulic motor 15 or the rotation buried pile 17 may be sufficient. Moreover, in the said Example, although the thing which press-molded the lower end of the steel pipe as the rotary embedding pile 17 and protruded three blades radially was shown, it may be what protruded two sheets, and also a spiral shape at the pile head. It can be applied to all piles that are rotary-embedded, such as those with blades attached.
[0029]
【The invention's effect】
As described above, according to the pile driving device of the rotary buried pile according to the first aspect of the present invention, a mechanism similar to the measuring device by the Swedish sounding method is incorporated in the pile driving device, and the rotation speed is adjusted with a constant pressure. Since the piles are measured while measuring the strength of the ground, it is possible to check whether the piles are piled up one by one up to the support layer according to the geological survey results, and the driving data can be managed as construction records. .
[0030]
Moreover, according to the pile driving device of the rotary buried pile according to claim 2, the drive unit for moving the pile rotation drive unit along the guide column rotates the chain hung along the guide column and the same. It is composed of a hydraulic motor, and the indentation pressure control unit controls the indentation pressure by measuring the pressure of the hydraulic pump that drives the hydraulic motor, so that a long rotating buried pile can be driven and the indentation pressure can be reduced. It can be controlled constantly.
[0031]
Further, according to the piled driving device of the rotary buried pile according to claim 3, the rotary buried pile is formed by pressing the lower end of the steel pipe and a plurality of blades are radially projected, so that the processing is easy and inexpensive. In addition to being able to be manufactured, the embedding speed is high, the residual soil is hardly discharged, and the frictional support force can be greatly improved.
[Brief description of the drawings]
FIG. 1 is a side view showing a pile driving device for a rotary buried pile according to an embodiment of the present invention.
FIG. 2 is a block diagram showing a configuration of a support layer confirmation device provided in the pile driving device of FIG. 1;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Pile-driving device 3 of a rotation buried pile 3 Car body 4 Support part 5 Lifting mechanism 6 Guide strut 7 Hydraulic cylinder 8 Hydraulic motor 9A Lower sprocket 10 Chain 11 Hydraulic pump 12 Hydraulic pump 13 Bracket 14 Pile rotation drive part 15 Hydraulic motor 16 Catcher 17 Rotation Embedded pile 18 Support ring 19 Support layer confirmation device 20 Indentation pressure control unit 21 Settlement amount measurement unit 22 Rotational speed measurement unit 23 Ground strength calculation unit 24 Display unit

Claims (3)

A pile rotation drive unit that holds and rotates the upper end of the rotary buried pile is attached to be vertically movable along a vertically supported guide column, and a lifting mechanism that moves the pile rotation drive unit along the guide column is provided. In a pile driving device for a rotary buried pile that is pushed into the ground while rotating the pile, a pushing pressure control unit that pushes the rotary buried pile at a constant pressure, a rotation speed measurement unit that measures the rotation speed of the pile, and settlement of the pile A pile driving device for a rotary buried pile comprising a subsidence measuring unit for measuring the amount, and a support layer confirmation device comprising a ground strength calculating unit for calculating ground strength from the number of rotations per unit subsidence. The drive unit that moves the pile rotation drive unit along the guide column is composed of a chain that is wound around the guide column and a hydraulic motor that rotates the chain, and the indentation pressure control unit controls the hydraulic motor. The pile driving device for a rotary buried pile according to claim 1, wherein the pressure of the hydraulic pump to be driven is measured to control the indentation pressure. The rotary embedded pile driving apparatus according to claim 1, wherein the rotary embedded pile is press-formed at the lower end of the steel pipe and a plurality of blades are radially projected.

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