JPH0959994A - Automatic attitude control system of press-in caisson - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable press-in efficiently by installing four groups of hydraulic jacks and a pair of auxiliary jacks to a press-in caisson and controlling the quantities of oil fed to each jack by a computer on the basis of attitude measuring data. SOLUTION: Press-in girders 21 are mounted around the upper section of a caisson body 19, center hole jacks 18 gripping cables from anchors 20 are set up at every two uniformly at the four quarters, and a pair of auxiliary jacks are separately arranged symmetrically. The quantities of oil fed to the jacks 18 in each group are controlled by a computer 12 for controlling an attitude on the basis of data from a bidirectional type attitude measuring means 22 fitted to the caisson body 19, and strokes are adjusted. The computer 12 controls an inverter 11 and a motor 13 for a variable displacement type hydraulic pump 14 under the state, in which all jacks 18 are operated, and changes the quantities of oil to each jack 18 in a stepless manner through a diverging device 17. When auxiliary pressure is required by the change of soil, the auxiliary jacks are operated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a press-fit caisson method, and more particularly to a caisson attitude control system which is indispensable for sinking a press-fit caisson.

[0002]

2. Description of the Related Art In recent years, a press-fit caisson method, which is an improved open caisson method, is being widely used in foundation work because it can surely sink down to a predetermined ground and is easy to construct and economical. In addition, the scale of the caisson structure is increasing, and the number of jacks for press-fitting and sunk caisson skeletons is now over ten.

Conventionally, when the press-fit caisson is to be sunk, excavated earth and sand or water is packed in a tank or the like for loading and installed on the upper part of the caisson skeleton to provide a load for press-fitting. Further, in the case of using the hydraulic jack for press-fitting, as illustrated in FIG. 3, the press-fitting hydraulic jacks 51 are evenly arranged in four directions on the upper part of the caisson body 50, and the press-fitting hydraulic jacks are divided into groups in each direction. The jack pressure of the jack 51 is changed, or each press-fitting hydraulic jack 5
The jack operation of No. 1 was manually turned on and off, and the caisson structure was controlled while being press-fitted and sunk. As this attitude control method, as shown in FIG. 4, the flow rate adjusting valve 56 adjusts the amount of oil from a hydraulic pump unit 54 including a variable displacement hydraulic pump 53 and an electric motor (motor) 52.
Or a pressure reducing valve 57 shown in FIG.
6 to control the jack pressure, or an ON / OFF control method based on a plurality of used jack selection methods including a throttle switching valve 58 and a switching valve 59 shown in FIG.

[0004]

However, the above-mentioned conventional method has raised the following problems. (1) In the case of the control by the flow rate adjusting valve described above, the viscosity changes due to the increase in the oil temperature, and therefore the flow rate changes even with the same valve opening, and it is difficult to secure a constant flow rate.
Therefore, delicate control is often impossible. (2) In the method of (1), since the discharge amount of the hydraulic pump is constant, a wasteful amount of oil flows due to the bypass, which causes an increase in oil temperature. (3) In the attitude control method for the caisson body, which manually turns on and off the hydraulic jack using a switching valve, etc., the hydraulic jack on the lower side of the body is stopped, and only the hydraulic jack on the higher side is operated intermittently. Attitude control.
Therefore, when the sinking resistance is large, the pressure input may be insufficient and the posture control may be difficult. (4) In the manual operation method of the hydraulic jack using the flow rate adjusting valve, the pressure reducing valve, the switching valve, etc., it is difficult to quickly respond to the posture of the caisson that changes with time, and the jack efficiency is poor. In addition, the equipment capacity also increases.

Therefore, the present invention not only solves the above-mentioned drawbacks and problems in the conventional caisson attitude control method, but also adopts a jack control system by hydraulic flow rate control that enables more delicate control, and the caisson structure Based on the data from the posture measuring means of the body provided in the, the amount of oil is controlled steplessly by the method of changing the frequency of the inverter motor built in the hydraulic unit by the computer according to the posture situation of each jack. By doing so, it is possible to control the posture with all the jacks always operating, and it was developed with the aim of providing an automatic posture control system for a press-fit caisson that is highly efficient and accurate, and that can handle large depths. is there.

[0006]

In order to achieve the above object, the present invention has a system configured as follows. First, a press-fit girder was installed around the upper part of the caisson skeleton, and a plurality of press-fit jacks for holding the cable from the ground anchor were evenly arranged on the press-fit girder. And
An operating means for activating the press-fitting jack is provided, and the body is provided with a posture measuring means for detecting the inclination of the body, that is, the verticality. Further, the present system is constituted by further providing an automatic operation means for judging the operation amount of each press-fitting jack based on the data from the posture measuring means and automatically controlling the operation of each press-fitting jack.

Further, the press-fitting girder is provided with an auxiliary press-fitting jack for applying an eccentric load to the body in an emergency.

The attitude measuring means is composed of a two-direction detection type inclinometer and a squat gauge.

A hydraulic jack is used as the press-fit jack.

The operation control is hydraulic flow rate control using a variable displacement hydraulic pump and an inverter motor.

Further, the automatic operation means is characterized in that the frequency of the inverter motor is controlled by a computer.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention. FIG. 1 is an overall configuration diagram showing an automatic posture control system for a press-fit caisson according to the present invention, and FIG. 2 is a schematic plan view showing an example of jack arrangement in a caisson according to the present invention. First, as shown in FIG. 1, a press-fit girder 21 was installed around the upper part of the caisson body 19, and a center hole jack 18 for holding a cable from an anchor (ground anchor) 20 for reaction force was installed.
As shown in FIG. 2, this jack is arranged such that four groups of press-fitting hydraulic jacks A (using the center hole jack 18) are arranged evenly in four directions, and mainly perform press-fitting and posture control. And In addition, a pair of auxiliary jacks B (the center hole jacks 18 are also used in this case) are symmetrically arranged in two directions on one side, and when four groups of press-fitting hydraulic jacks A alone do not perform good posture control. , Eccentric load was applied to facilitate control. In other words, the number of jacks and thrust set in advance considering the soil quality and caisson shape, etc. are used when auxiliary pressure input is required due to changes in the soil quality or more delicate control is required. I decided to do it.

Further, in the present invention, the control of the pressure input of the center hole jack 18 for press-fitting is performed by the hydraulic flow rate control. As shown in FIGS. 1 and 2, this is a variable displacement hydraulic pump 1 for each jack group.
4 is installed, and the rotation speed of the electric motor (motor) 13 that drives the variable displacement hydraulic pump 14 is directly controlled by the inverter 11. This inverter 11 is based on tilt angle data and the like from the attitude measuring means 22 including a two-direction detection type inclinometer and a squat gauge provided in the caisson body 19,
The attitude control computer 12 that calculates the operation amount of each jack group is controlled in the form of frequency change. The center hole jacks 18 are then divided into groups.
In addition, the stroke of the jack is adjusted by sending a properly controlled amount of oil through the branching device 17. Thus, the automatic attitude control system for the press-fit caisson is configured. For this reason, it is possible to reduce the increase in the oil temperature, which has been a problem in the related art, to save power, and to reduce the generation of useless oil.
In this system, with all the jacks in operation, the maximum amount of oil is changed to the jack on the high slope side, and the small amount of oil is changed to the low side jack infinitely.

Although not shown, the caisson bottom is excavated by using a bucket or the like. When the predetermined excavation is completed in this way, the hydraulic flow rate of the jacks in each group is adjusted so that the caisson body 19 becomes vertical, and an electric motor 13 for moving the attitude control computer 12, the inverter 11, and the variable displacement hydraulic pump 14. The caisson body 19 is press-fitted into the ground while being controlled in cooperation with the. The attitude control system according to the present invention is basically based on four-system control, and the number of jacks is preferably a multiple of four.

[0015]

Since the present invention is configured as described above, it has the following effects. (1) In the system according to the present invention, since the caisson posture control is performed with all the jacks constantly operating, the pressure input can be set to a larger value as compared to manual operation, and efficient control can be performed and at a large depth. Can also handle. (2) The system according to the present invention uses the hydraulic flow rate control method and changes the frequency of the inverter motor incorporated in the hydraulic unit according to a command from the computer to control each jack in accordance with the posture condition, that is, The attitude control performance of the caisson is improved because the attitude control is performed when all the jacks are always in operation. Therefore, the construction accuracy is improved and the construction period is shortened. (3) The system according to the present invention does not require a large number of switching valves and the like as compared with the conventional press-fitting system, and the facilities such as power for control can be greatly saved. (4) The system according to the present invention can significantly reduce the cost as compared with the conventional proportional control valve system. (5) In the system according to the present invention, the attitude of the caisson immediately before control is measured by a computer by means of an inclinometer provided on the skeleton, and the control amount in each direction for returning the skeleton to the correct vertical state is determined from the shape and size of the caisson. Since it is possible to calculate in advance how much difference should be made to the current jack stroke in the direction at the end time, it is possible to grasp the control amount in advance.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing an automatic attitude control system for a press-fit caisson according to the present invention.

FIG. 2 is a schematic plan view showing an example of jack arrangement in the caisson of the present invention.

FIG. 3 is a schematic plan view showing an example of jack arrangement in a conventional press-fit caisson.

FIG. 4 is a conceptual diagram showing a control method by a jack flow rate adjusting valve in a conventional press-fit caisson posture control system using a hydraulic jack.

FIG. 5 is a conceptual diagram showing a control method of a jack pressure reducing valve in a conventional press-fit caisson posture control system using a hydraulic jack.

FIG. 6 is a conceptual diagram showing a control method using a jack selection method in a conventional press-fit caisson attitude control system using a hydraulic jack.

[Explanation of symbols]

 10 ... Power source 11 ... Inverter 12 ... Attitude control computer 13 ... Electric motor (motor) 14 ... Variable displacement hydraulic pump 15 ... Hydraulic pump unit 16 ... Relief valve 17 ... -Branching device 18 ... Center hole jack 19 ... Caisson body 20 ... Anchor 21 ... Press fit girder 22 ... Posture measuring means 50 ... Caisson body 51 ... Press fit hydraulic jack 52. ..Electric motor (motor) 53 ... variable displacement hydraulic pump 54 ... hydraulic pump unit 55 ... relief valve 56 ... flow rate adjusting valve 57 ... pressure reducing valve 58 ... throttle switching valve 59. ..Switching valve A ... Press-fit hydraulic jack B ... Auxiliary jack

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshimi Fujitani 1-25-1 Nishishinjuku, Shinjuku-ku, Tokyo Taisei Corporation

Claims (6)

[Claims] 1. A press-fit girder installed around the upper part of a caisson skeleton, a plurality of press-fit jacks for evenly arranging cables from ground anchors arranged on the press-fit girder, and an operating means for activating the press-fit jack. In the attitude control system of the press-fit caisson including the attitude measuring means of the body provided in the caisson body, the attitude control system determines the operation amount of each of the press-fitting jacks based on the data from the attitude measuring means, An automatic attitude control system for press-fit caisson, which is equipped with automatic operation means that automatically controls the operation of each press-fit jack. 2. The automatic attitude control system for a press-fit caisson according to claim 1, wherein the press-fit girder is provided with an auxiliary press-fit jack for applying a eccentric load to the body in an emergency or the like. 3. The automatic attitude control system for a press-fit caisson according to claim 1, wherein the attitude measuring means comprises a two-direction detection type inclinometer and a squat gauge. 4. The automatic attitude control system for a press-fit caisson according to claim 1, wherein the press-fit jack is a hydraulic jack. 5. The automatic attitude control system for a press-fit caisson according to claim 1, wherein the operation control is a hydraulic flow rate control using a variable displacement hydraulic pump and an inverter motor. 6. The automatic attitude control system for a press-fit caisson as claimed in claim 1, wherein the automatic operation means controls the frequency of the inverter motor by a computer.