JPH0216413B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a device for press-fitting pile bodies into the ground, and is particularly suitable for use in narrow spaces, and is suitable for underpinning work, especially pile increase work for construction foundations. This invention relates to a pile body press-in device for use.

As is well known, during construction work, if the existing foundation piles do not reach the supporting ground or the required depth, the building will sink, which is called uneven settlement.
Therefore, it is necessary to increase the number of piles and reinforce the existing foundation. As shown in Figure 5, this pile increase work involves digging beneath the foundation (footing) of the structure, and installing one pile (a) separately along the existing pile (a) to a sufficient depth. Alternatively, multiple piles are press-fitted, and the pile body is a thick-walled steel pipe with a length of about 1 m and a diameter of about 30 to 50 cm, and a jack is inserted between the top of the pile and the lower surface of the structure's foundation, and the pile is press-fitted into the ground. The steel pipes are successively added by welding to reach the required depth. However, with this method, each time a steel pipe of a predetermined length is press-fitted, it is necessary to remove the jack that has already been installed under the building foundation and reinstall it under the next foundation.
Furthermore, in this method, new piles are press-fitted where existing piles are, so the work area is extremely narrow and the work cannot be completed smoothly.

The present invention has been made to eliminate the above-mentioned drawbacks of the prior art, and provides a device that improves work efficiency by holding a jack on the underside of a building foundation and rotating it while press-fitting a pile body. It is something to do.

An embodiment of the present invention will be described with reference to FIGS. 1 and 2. Reference numeral 1 denotes a base, which is formed in the shape of a horseshoe with one side cut inward, and a box-tube-shaped support 3 is erected at the back of this cut 2. Reference numeral 4 denotes a jack, which is attached downward to the tip of the horizontal rod 5, and whose vertical portion 6, which is connected to the base end of the horizontal rod 5, is fitted into the support column 3 and supported in a cantilever manner. This jack 4 is a 50 ton jack as an example,
It is provided directly above the notch 2, and the plunger 7 is moved up and down by hydraulic pressure. The jack 4 itself can be raised and lowered via the column 3 by means of a lifting cylinder 8 provided on the surface of the base 1.

At the lower end of the plunger 7 of the jack 4, a chuck 9 to be engaged with the top of the pile body is rotatably attached to the plunger 7, for example, a thrust bearing 10.
It is attached via. This chuck 9 has an engaging protrusion 11 to be engaged with the head of the pile body a, and is formed as a single spur gear having a toothed edge on its peripheral surface. This tooth edge 12 engages with a pinion 14 extending in the vertical direction, which is rotated via a hydraulic motor 13 provided on the base 1, and rotates at a low speed (for example,
24 times/minute). That is, as shown in FIG. 2, a vertical shaft 17 that is rotated by a hydraulic motor 13 provided on a base 1 via gears 15 and 16 has upper and lower ends protruding from upper and lower bearings 18 on the support column 3. , 19, and a long pinion 14 is fitted onto the shaft, and the chuck 9 engages the toothed edge 12 on its circumferential surface with the pinion 14 and rotates while moving up and down. .

The pile rotary press-in device according to the present invention has the above-mentioned configuration, and the method of using this device is as follows.

As in the case of the conventional method shown in FIG. 5, first, the base 1 is installed by digging under the foundation of the structure, and the jack 4 is raised by the lifting cylinder 8 to move the upper surface of the horizontal rod 5 to the structure foundation. make contact with the bottom surface of the

Next, with the plunger 7 of the jack 4 raised, the pile body a is positioned between the jack 4 and the ground, and then the plunger 7 is lowered, and the jack 9
The engaging protrusion 11 is engaged with the notch 20 provided at the top of the pile body a. The hydraulic motor 13 is driven to rotate the pile body a, and the jack 4 is operated to lower the plunger 7, and the weight of the structure is used as a reaction force to rotate the pile body and press it into the ground. Continue pressing until the top of pile a is slightly exposed on the ground surface. When the specified press-fitting is completed, the plunger 7 is raised, the next pile body a is placed on top of the previously press-fitted pile body a, and after welding the periphery of the placed part, the chuck 9 is attached to the upper pile. The pile body is engaged with the notch 20 at the top of the body a, and the rotary press-fitting operation of the pile body is performed again. This operation is repeated sequentially, and when the lowest end of the connected pile bodies a reaches the supporting ground or reaches a predetermined depth, the entire device is moved and removed, and the press-fit is completed. The fixing material is inserted and fixed between the top end of the pile body and the lower surface of the structure's foundation, and the work is completed by backfilling the excavated area.

As explained in detail above, according to the present invention,
Compared to the conventional construction method, in which a jack is fixed to the bottom surface of the structure's foundation at each pile press-in position and the pile is press-fitted one by one, the jack 4 is attached and held on the base 1. Because of this, there is no need to attach or remove the jack every time a specified length of pile is press-fitted, and since the pile is press-fitted while rotating, the press-in speed is significantly increased, greatly improving work efficiency compared to conventional methods. can be improved. Note that the pile body can be used by forming a notch in the top surface of a conventional steel pipe.

Figure 3A shows a system in which a crawler 21 is provided on the underside of the base 1 to allow the entire device to move independently, and Figure 3B shows a system in which the base 1 is shaped like a trolley and a rail-shaped laying base 22 is moved back and forth. It shows something that can be moved freely via a cylinder. FIG. 4 shows a gear case 24 housing a gear 23 which engages with the toothed edge 12 of the jack 9 at the lower end of the plunger 4 instead of the pinion 14 extending vertically in the previous embodiment.
This shows a device that is fitted so that it can slide up and down along the In this case, there is an advantage that the vertical shaft 17 can be manufactured at a very low cost by making it a spline shaft or having a feather key groove.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of the implementation of the device of the present invention, FIG. 2 is a front view thereof, FIGS. 3A and B are diagrams showing other embodiments of the device of the present invention, and FIG. 4 is a diagram of the device of the present invention. FIG. 5, which is a diagram showing the implementation state, is a diagram for explaining the conventional pile increasing work. Codes in the figure: 1...base, 2...notch, 3...
...Strut, 4...Jacket, 5...Horizontal rod, 6...
Vertical part, 7...Plunger, 8...Lifting cylinder, 9...Chuck, 10...Thrust bearing, 11...Engaging protrusion, 12...Tooth edge, 13...
Hydraulic motor, 14... Pinion, 15, 16...
Gear, 17... Vertical shaft, 18, 19... Bearing, 20
... cut section, 21 ... crawler, 22 ... laying base, 23 ... gear, 24 ... gear case.

Claims (1)

[Claims] 1. A jack that ascends and descends along a support provided on a horseshoe-shaped base is installed downward on a horizontal rod that contacts the lower surface of the building foundation, and a gear-shaped chuck is formed at the lower end of the plunger of the jack to engage with the pile body. A pile rotary press-fitting device characterized in that the gear is connected to a vertical shaft connected to a power source so as to be slidable up and down and rotatable.