JPH021929B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for press-fitting steel pipe bodies such as steel pipe sheet piles and steel pipe piles into soil.

In recent years, due to pollution problems such as vibration and noise in construction and civil engineering work, attempts have been made to install steel pipe bodies without vibration or noise, instead of using diesel hammers. The steel pipes are installed by press-fitting them instead of driving them. By the way, when a steel pipe body is press-fitted into the soil using such a press-in machine, an auger machine is also used to press-fit it, but since there is a limit to the press-in force of the press-in machine, the pile core of the steel pipe body Unless the vertical accuracy is precisely controlled, there is a risk that once the steel pipe body tilts, it will not be possible to correct it. When steel pipe sheet piles are continuously driven in a ring shape to form a well, such an inclination makes it difficult to construct the final closing pile and the ring cannot be closed. When pouring concrete vertically, vertical accuracy must be particularly high.

However, in the past, vertical accuracy was controlled by visually observing the steel pipe body built on a specified ground using a transit from two mutually orthogonal directions (x direction and y direction), and driving the steel pipe body while checking the vertical direction of the steel pipe body. was. For this reason, as the driving progresses and the length of the pile remaining on the ground becomes shorter, it becomes difficult to visually detect the inclination of the steel pipe body, and the detection accuracy decreases.
In addition, in the case of joint piles, since the lower pile is buried underground with the head remaining, it is difficult to perform the weld joint while keeping the upper and lower piles completely vertical due to the poor end surface accuracy of the steel pipe body. It was completely impossible. Most importantly, even if the tilt of the steel pipe body is detected visually via the transit, in order to correct the tilt based on this data, the press-fitting machine must be stopped every time a tilt occurs, and the tilt can be corrected manually in this state. This had to be done manually, which was extremely time-consuming and labor-intensive.

The present invention has been made in view of these points, and its purpose is to provide a method for press-fitting a steel pipe body, which can easily and quickly perform press-fitting while maintaining high vertical accuracy of the steel pipe body. It is in.

To explain the present invention below, the present invention lowers a holding part that tightens and holds the outer circumferential surface of a steel pipe body such as a steel pipe pile or steel pipe sheet pile using a plurality of push jacks connected to the holding part, and then lowers the steel pipe body into the ground. When press-fitting into the pipe, a control circuit that receives the output of an inclinometer that detects the direction and amount of inclination of the steel pipe temporarily stops the operation of one of the push-in jacks while continuing the operation of the other push-in jack. In particular, the inclination of the steel pipe body is automatically corrected while press-fitting is in progress.The details will be explained below based on an example of the apparatus shown in the drawings.In the figure, 1 indicates a steel pipe body which is a steel pipe sheet pile. It has joint parts 11, 11 on both sides. This steel pipe body 1 has a drilling blade 13 attached to its lower end and is press-fitted by a press-fitting machine 2 into a hole drilled by an auger 12 which is inserted into the steel pipe body 1 . As shown in FIGS. 2 and 3, the press-fitting machine 2 includes a pedestal 21 provided with a large-diameter hole in the center through which the steel pipe body 1 is inserted, and push-in jacks placed at each of the four corners of this pedestal 21. 3 and a tightening frame 4 that is moved up and down by these four push-in jacks 3. Each push-in jack 3 supports a spherical portion at the lower end on a seat 22 on a pedestal 21, for example. It is a hydraulically driven type that can be tilted freely within a certain range in all directions by tilting, etc., and can be moved horizontally within a minute range. The tightening frame 4, which is a holding part that tightens and holds the outer peripheral surface of the steel pipe body 1, is 4
It is formed by connecting two arc-shaped members 23 in an annular manner with two pivots 24 and two tightening cylinders 25, and the upper part of the push-in jack 3 is fixed to each arc-shaped member 23, respectively. . FIG. 4 is a hydraulic circuit diagram of this press-fitting machine 2, in which the discharge side of the hydraulic pump 26 and the tank 27 are connected to each pushing jack 3 via an electromagnetic-hydraulic control type switching valve 7 with 4 ports and 3 positions. It is connected to both ends of the tightening cylinder 25 via a switching valve 28.

The inclinometer 5 outputs as an electrical output the amount of inclination (inclination angle) in one direction or in x and y directions perpendicular to each other due to changes in its posture.
It is attached to the push-in jack 3 of the press-fitting machine 2 so as to be able to detect inclinations in both x and y directions. A control circuit 6 is provided on the operation panel (not shown) for controlling the switching valve 7 corresponding to each push-in jack 3 of the press-fitting machine based on the detection output of the inclinometer 5 to correct the inclination. 5, switching valve 7,
It is connected to the switching valve 28.

Therefore, by installing the press-fitting machine 2 on a horizontal surface and contracting the tightening cylinder 25, the tightening frame 4 is attached to the steel pipe body 1.
If each switching valve 7 is switched in one direction while the outer circumferential surface of
is lowered vertically and the steel pipe body 1 is press-fitted into the soil. If the steel pipe body 1 is tilted, for example, in the x direction, the push jack 3 is also tilted at this time, so this tilt is detected by the inclinometer 5, and the control circuit receives the tilt direction and the tilt amount. 6 stops the operation of one of the two push-in jacks 3 on the x-axis via the switching valve 7, and continues the operation of the other three push-in jacks 3 until the steel pipe body 1 returns to vertical. Then, make the vertical correction, and once the correction is completed, press the jack all the way again 3.
Activate. When one stroke of the pushing jack 3 is completed, the control circuit 6 immediately extends the tightening cylinder 25 and loosens the tightening frame 4 in response to an input from a limit switch or the like that detects this, and in this state, each switch is changed. The valve 7 is switched to the other side, the full push-in jack 3 is extended, and the tightening frame 4 is moved upward.
When the extension of each pusher jack 3 is completed, the control circuit 6 causes the tightening frame 4 to tighten and the pusher jack 3 to lower the tightening frame 4 in response to an input from a limit switch or the like. Resume press-fitting. At this time, if the steel pipe body 1 is tilted in both the x and y directions, the control circuit 6 controls the operation of each pushing jack 3 in both the Stop until the tilt in each direction is corrected. In this way, the inclination of the steel pipe body 1 is automatically corrected during the press-fitting operation.
This means that the parts are press-fitted.

The inclinometer 5 does not necessarily need to be attached to the push jack 3 of the press-fitting machine, and may be attached directly to the steel pipe body 1, but in this case, although the accuracy of detecting the inclination of the steel pipe body 1 is increased, the wiring process is troublesome. In addition, it is necessary to install the inclinometer 5 in accordance with both the x and y directions set in the control circuit 6 and the press-in machine 2, and if you make a mistake, you will not be able to correct the inclination. It is preferable to attach it to jack 3. Also, inclinometer 5
In order to improve the accuracy of inclination detection when the inclinometer 5 is attached to the push jack 3, as shown in FIG. It is preferable that the control circuit 6 takes the average value of the inclination amount output from the inclinometers 5x, 5x, 5y, and 5y in each direction for the inclination in each of the x and y directions. That is, if the inclination amount outputs in each x direction from two inclinometers 5x, 5x on the x direction are a, b,
The switching valve 7 uses (a+b)/2 as control data. As shown in FIGS. 6a and 6b, the actual amount of inclination of the steel tube 1 and the amount of inclination of the push-in jack 3 detected by the inclinometer 5 may differ depending on the contact between the clamping frame 4 and the steel tube 1. Even if the sensor is tilted, this can be corrected and the tilt detection accuracy can be improved.

In addition, in the illustrated example, the number of push-in jacks 3 is 4.
In this book, two hydraulic jacks 3 are arranged on each axis in both the x and y directions, but the arrangement of the x and y directions is arbitrary. Of course, even if the number of push-in jacks 3 is three at 120° intervals, the inclination direction that can be detected by the inclinometer 5 attached to each push-in jack 3 can be determined by x, e, f at 120° intervals. The control circuit may control the three pusher jacks 3 based on these data. in this case,
The amount of inclination in the x, e, and f directions may be converted into the amount of inclination in the xy direction and the push jacks 3 may be controlled based on this. Therefore, the number of push jacks 3 and the number of inclinometers 5 It is okay for the two to be different.

As described above, in the present invention, the inclination of the steel pipe body is automatically corrected by controlling the push-in jack with a control circuit that inputs the output of the inclinometer, and this correction is performed while the press-fitting operation is in progress. This method allows the steel pipe body to be press-fitted easily and quickly while maintaining high vertical accuracy.

[Brief explanation of drawings]

FIG. 1 is a front view of an apparatus according to an embodiment of the present invention, FIGS. 2 and 3 are a front view and a plan view of the same press-fitting machine, and FIG. 4 is a hydraulic circuit diagram of the same press-fitting machine.
FIG. 5 is a schematic plan view of the device of another embodiment, FIGS. 6 a and b are explanatory views of the same operation, and FIG. 7 is a schematic plan view of the device of still another embodiment. 1 is a steel pipe body. ,2
3 is a press-fitting machine, 3 is a push-in jack, 4 is a tightening frame as a holding part, 5 is an inclinometer, and 6 is a control circuit.

Claims (1)

[Claims] 1. When pressing the steel pipe body into the soil by lowering the holding part that tightens and holds the outer circumferential surface of the steel pipe body such as a steel pipe pile or steel pipe sheet pile using multiple push jacks connected to the holding part, the steel pipe body A steel pipe body characterized in that the operation of one of the push jacks is temporarily stopped while the operation of the other push jack is continued by a control circuit that receives as input the output of an inclinometer that detects the direction and amount of inclination of the steel pipe body. Press-fitting method.