JP2009002127A - Method for operating on-vehicle type soil improving apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for operating an on-vehicle type soil improving apparatus capable of obtaining stable improved soil by adding a required minimum amount of solidifying agent into pretreated soil in a treatment method of mud and muddy water produced in underground excavation jacking work and underground continuous wall construction work, and preventing the overload stop of a motor for rotating a shaft of a two-shaft paddle screw conveyor. <P>SOLUTION: The on-vehicle type soil improving apparatus for mud and muddy water produced in underground excavation jacking work and underground continuous wall construction work is operated by repeating normal rotation and reverse rotation of the mixing-agitating-conveying two-shaft paddle screw conveyor for reacting a solidifying agent on the pretreated soil to obtain improved soil. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for treating mud mud generated in underground excavation promotion work and underground continuous wall construction work.

In underground excavation propulsion work and underground underground wall construction work, when excavating underground, underground water may flow out. Therefore, it is an obstacle to excavation work, and the work is continued while draining with a submersible pump etc., but the water that flows out during such excavation contains a lot of earth and sand, so it is highly turbid and remains as it is It is legally regulated to discharge in
Moreover, not only the outflowing water but also the excavated sediment must be treated as industrial waste.

  Therefore, the present inventor, as shown in FIG. 1, shows that the mud mud water 1 pumped up from the excavation site passes through the vibrating screen 4 (lower stage) from the receiver tank 3 to obtain a liquid component containing rough solids and sludge. This liquid component is sent to the mixing and stirring tank 12, flocculant is added to flocate the sludge, transferred to the precipitation tank 14, solid-liquid separated in the precipitation tank 14, and the supernatant water is treated water. The flocs that have been discharged and settled are further separated into solid and liquid through the vibrating sieve 4 (upper stage), and the liquid component is transferred to the mixing and stirring tank 12 and circulated in the system, and the rough solid from the previous vibrating sieve 4 (lower stage). A method was proposed in which a solidifying agent was added and stirred and mixed as a pre-treated soil while being conveyed by a paddle screw conveyor 8 together with the flocs from the vibrating sieve 4 (upper stage) and discharged as improved soil 20. (See Patent Document 1)

  However, since this soil quality improvement device is a vehicle-mounted type, the length of the biaxial paddle screw conveyor is limited, so that sufficient mixing and stirring of the pretreated soil such as clay and the solidifying agent is required. In such a case, there has been a problem that the mixing and stirring ability is insufficient, and it has to be dealt with by using an excessive amount of the solidifying agent.

In addition, there has often been a problem that the motor of the biaxial paddle screw conveyor that mixes and stirs this pretreated soil with a solidifying agent is overloaded due to gravel biting or the like. In that case, the work is resumed after the screw is reversely rotated to partially return the overload portion, but it is impossible to predict and it is necessary to attach an operator.
Patent Literature Japanese Patent Application No. 2006-357189

  Accordingly, an object of the present invention is to obtain a stable improved soil by adding a necessary minimum solidifying agent to the pretreated soil, and to prevent an overload stop of the shaft rotation motor of the two-shaft paddle screw conveyor. It is providing the operation method of the vehicle-mounted type soil improvement apparatus which can be performed.

  As a means for solving the above problems, the present invention provides an improved soil by reacting a pretreatment mud and a solidifying agent in an in-vehicle soil quality improvement device for mud mud generated in underground excavation propulsion work or underground continuous wall construction work. For this purpose, the biaxial paddle screw conveyor for mixing and agitating and transporting is rotated and rotated at regular intervals.

  According to the present invention, since the length limitation of the biaxial paddle screw conveyor can be substantially eliminated, stable operation can be performed by adding the planned solidifying agent amount regardless of the excavated soil quality.

  In addition, it is possible to easily prevent an overload stop of the shaft rotation motor of the two-axis paddle screw conveyor, thereby reducing the amount of work for the operator.

  Furthermore, the mud soil adhering to the paddle is wiped off by the impact caused by switching between forward and reverse rotation, and the rotation can be prevented, and the stirring and mixing effect and the conveying effect are remarkably enhanced particularly in the case of clay.

  Hereinafter, the present invention will be described with reference to FIGS.

  FIG. 1 shows an embodiment of a mud mud water treatment apparatus used for carrying out the present invention. The mud mud water receiver tank 3 is decompressed by a blower (not shown), and the mud mud water 1 is pumped up by a hose 2 there. The mud mud 1 is supplied to the vibrating screen 4 from there, and solids such as gravel and clay are dropped onto the biaxial paddle screw 8, and the liquid is cyclone by the pump 6 via the primary treatment tank 5. 7, the cyclone under part is returned to the vibrating screen 4, and the solid part is combined with the gravel, clay, etc. of the primary treatment on the biaxial paddle screw 8.

  The cyclone-treated liquid is stored in the notch tank 10, and depending on the excavated soil, it is neutralized with carbon dioxide gas, dilute sulfuric acid, etc., and sent to the stirring tank 12 by the pump 11. The floc of the sludge is achieved by mixing and stirring with the flocculant. The flocified liquid overflows from the agitation tank 12 and moves to the sedimentation tank 14 to precipitate the floc, and the supernatant water overflows and is transferred to and stored in the supernatant water tank 16 to which the baffle plate 17 is attached. It is cycled as dilution water for the liquid and washing water for the solid-liquid separation process of the vibrating screen 4.

  Further, the surplus water (discharged water 19) in the upper part of the supernatant water tank 16 overflows and is discharged into a drain or a river.

  The precipitated floc is sent to the vibrating screen 4 by the pump 15 and dehydrated together with the gravel and clay of the mud mud 1, and the dewatered floc mixed with the gravel and clay is also on the biaxial paddle screw 8. Are mixed with the solidifying agent from the solidifying agent silo 9 by the biaxial paddle screw 8 and recovered as the improved soil 20.

As shown in FIGS. 2 and 3, the biaxial paddle screw conveyor 8 for mixing and agitating and used for carrying out the present invention is adjusted to the angle of the bracket 26 and the biaxial paddle screw conveyor 8 on the loading platform 22 of the vehicle-mounted vehicle. It is mounted via a screw-type jack 21 for use, and is provided with a pretreatment mud inlet 23, a solidifying agent inlet 25 from the solidifying silo 9, and an improved soil outlet 24.
Further, the forward / reverse rotation of the biaxial paddle screw conveyor 8 is switched by the action of a relay (not shown) linked with a timer (not shown).

  The operating state of the biaxial paddle screw 8 during operation is shown in FIG. 4 including interlocking with other devices. That is, when the mud mud receiver tank 3 is detected to be full, mud mud is sent to the vibrating screen 4 and solids such as gravel and clay fall onto the biaxial paddle screw 8 and the paddle switch 30 is turned on. 8 starts to rotate forward and enters a state of a. At the same time, the transport of the solidifying agent from the solidifying agent silo 9 is started, and both stop when the time set in advance in the timer comes. Then, when the time set in the timer elapses after moving to the mouth state, only the two-axis paddle screw 8 starts to rotate backward, stops when the time set in the timer comes, and further enters the timer in advance. When the set time has elapsed, the operation to return to the state of (a) is repeated, the receiver tank 3 is emptied, and the fall of solids such as gravel and clay on the biaxial paddle screw 8 stops and the paddle switch When 30 is cut off, the biaxial paddle screw 8 enters a stopped state, and the solid state such as the next gravel and clay falls onto the biaxial paddle screw 8 and the paddle switch 30 is turned on, so that the state of i is resumed. As a result, sequence control is performed.

  Next, an example of the operation of the embodiment will be described.

  By detecting the full capacity of the mud mud receiver tank 3, mud mud water is sent to the vibrating screen 4, and solids such as gravel and clay fall on the biaxial paddle screw 8 and the paddle switch 30 is turned on. At that time, the biaxial paddle screw 8 starts to rotate forward, and at the same time, the solidifying agent conveyance of the amount corresponding to the solid content from the solidifying agent silo 9 is started.

  Then, after the biaxial paddle screw 8 is normally rotated for 30 seconds by the timer (a state), the rotation of the biaxial paddle screw 8 and the transport of the solidifying agent from the solidifying silo 9 are stopped. Thereafter, the biaxial paddle screw 8 is stopped for 5 seconds to prevent gear crash. Next, the biaxial paddle screw 8 is reversely rotated for 15 seconds. As a result, the solid content mixed with the solidifying agent is returned to a distance that is half of the distance traveled during the forward rotation. Thereafter, the biaxial paddle screw 8 is put into a stopped state for 5 seconds to prevent a gear crash (b).

  When the state of (b) ends, the operation of returning to the state of (a) is repeated, and the improved soil 20 is discharged from the discharge port 24 of the biaxial paddle screw 8. This operation is continued until the dropping of the solid content onto the biaxial paddle screw 8 stops and the paddle switch 30 is turned off.

  In this way, in the in-vehicle two-axis paddle screw conveyor 8 with a limited length, in this example, the stirring and kneading effect substantially equivalent to about three times the length is obtained by the method of two steps and one step back. Therefore, stable operation can be performed by adding the planned amount of solidifying agent regardless of the excavated soil. The processing amount can also be controlled by accelerating / decelerating the rotational speed of the biaxial paddle screw conveyor 8 by an inverter.

  In addition, because the forward / reverse rotation is repeated in a short time, removal and crushing are automatically performed even if gravel is bitten, and it is easy to stop overloading of the shaft rotation motor of the 2-axis paddle screw conveyor 8 Therefore, the amount of work for the operator can be reduced.

  Furthermore, the mud soil adhering to the paddle is wiped off by the impact caused by switching between forward and reverse rotation, and the rotation can be prevented, and the stirring and mixing effect and the conveying effect are remarkably enhanced particularly in the case of clay.

  It is explanatory drawing which shows the outline of the mud mud water processing apparatus to which this invention is applied.   The top view (2-1) and side view (3-2) for description of the biaxial paddle screw of this invention.   Side surface sectional drawing of the vehicle-mounted type soil improvement apparatus of this invention.   The operation state figure when the biaxial paddle screw of this invention is rotated forward / reversely for every fixed time.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Mud mud 3 Receiver tank 4 Vibrating screen 5 Primary treated water tank 7 Cyclone 8 Twin screw paddle screw 9 Solidifying agent silo 10 Notch tank 12 Agitation tank 13 Coagulant spraying device 14 Settling tank 16 Supernatant water tank 17 Baffle plate 19 Effluent water 20 improved soil 21 screw type jack 22 loading platform 23 loading port 24 discharging port 25 solidifying agent loading port 26 bracket 27 supporting hole 28 supporting shaft 29 motor 30 paddle switch

Claims (1)

  2-shaft paddle screw conveyor for mixing and agitating and conveying to improve soil by reacting pretreatment mud and solidifying agent in the on-board soil quality improvement equipment generated by underground excavation and underground continuous wall construction The biaxial paddle screw conveyor operating method is characterized by repeatedly operating forward and reverse rotation at regular intervals.

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