JP5521666B2 - Construction method of soil cement wall - Google Patents

Description

The present invention also relates to the construction how the soil cement wall.

  An example of a method for constructing a soil cement wall is described in Patent Document 1. In this soil cement construction method, an excavator equipped with a pair of excavating wheels is used, and the ground is excavated by the excavator to form a groove. At this time, solidifying liquid is supplied from the liquid line into the excavated groove. The soil cement wall that matches the shape of the groove is built in the groove by supplying gas from the gas line and stirring and mixing the earth and sand produced by excavation in the groove and the solidifying liquid. .

  By the way, in the excavator used in the method for constructing the soil cement having the above-described configuration, the liquid supply nozzle of the liquid line for supplying the solidifying liquid is disposed above the pair of excavating wheels, and the gas for supplying the gas is used. A gas supply nozzle of the line is disposed in a portion adjacent to the upper liquid supply nozzle between the pair of excavating wheels.

  For this reason, when the earth and sand produced by excavating the ground with a pair of excavating wheels are entangled between the two excavating wheels and flowed upward, the gas and the solidifying liquid supplied above the two excavating wheels are separated from the earth and sand. This hinders the upward flow, significantly lowers the excavation efficiency of the ground by the excavating wheel, and agitates the earth and sand excavated by the excavating wheel as a result, leading to an increase in wear of the excavating wheel.

  Further, since the liquid supply nozzle for supplying the solidifying liquid and the gas nozzle for supplying the gas are disposed adjacent to each other, the solidifying liquid is blown upward by the gas before the solidifying liquid is mixed with the earth and sand. Therefore, it becomes difficult to uniformly stir and mix the solidified liquid and the earth and sand, and the quality of the soil cement wall is deteriorated.

  In addition, if the ground is a geology that contains clay soil, the clay soil adheres to the surroundings of each excavation wheel, and each excavation wheel becomes unrotatable, requiring work to remove the viscous soil adhering to the excavation wheel. Thus, the efficiency of construction of the soil cement wall is greatly reduced.

JP 2006-57447 A

The present invention has been made in view of the above-described conventional problems, and can construct a high-quality soil cement wall in a groove excavated in the ground, without being affected by the geology of the ground. , and to provide a building how the soil cement wall that can efficiently build a high-quality soil cement wall in a groove excavated in the ground.

In order to solve the above problems, the present invention employs the following means.
That is, the present invention is a method for constructing a soil cement wall by a suspended excavator in which a horizontal multi-axis rotary cutter is provided at a lower part of a frame, wherein the suspended excavator is lowered while lowering the suspended excavator. Grooves are excavated in the ground by rotating the horizontal multi-axis rotary cutter, and the excavated earth and sand are raised between the adjacent rotary cutters. At this time, in the lower part of the horizontal multi-axis rotary cutter Above the mixture that has been discharged through the stable liquid for excavation and mixed with the excavated earth and sand, and air is jetted from the upper part of the horizontal multi-axis rotary cutter, and rises between the adjacent rotary cutters. An excavation step that promotes the flow of the fluid into the plurality of rotary cutters; And a forming step of stirring and mixing the mixture that has been discharged through a portion below the portion that injects the air and that has risen between the adjacent rotary cutters, and the forming stabilizing liquid. It is characterized by.

According to the method for constructing a soil cement wall of the present invention, in the excavation process, the earth and sand produced by excavating the ground with a horizontal multi-axis rotary cutter are efficiently stirred and mixed, and the adjacent rotary It can flow upwards between the cutters.
Therefore, the abrasion of the rotary cutter is not increased by stirring the earth and sand produced by excavating the ground as it is, and even if the ground is a geology containing viscous soil, There is no such thing as sticking around the cutter and making the rotary cutter unrotatable.
Furthermore, in the creation process, the stabilizing liquid does not float upward by the air injected, and the mixture of earth and sand and the drilling liquid stabilizing liquid and the stabilizing liquid can be efficiently stirred and mixed. High quality soil cement wall can be constructed.

  Further, in the present invention, the excavating stabilizer is bent along the outer periphery of each rotary cutter, and the excavating stabilizer is discharged toward the lower portion between the adjacent rotary cutters. At least one air injection pipe having a plurality of injection holes, or a plurality of injections, which is discharged from the tip opening of the pipe and the air is horizontally provided in at least one stage above the horizontal multi-axis rotary cutter The forming stabilizing liquid is sprayed from the spray holes of the air spray plate having holes, and is provided above the horizontal multi-axis rotary cutter and in a portion below the air spray pipe or the air spray plate. It is good also as discharging toward the upper part between the said adjacent rotary cutters from the produced stable liquid discharge pipe.

According to the method for constructing a soil cement wall according to the present invention, the stable liquid for excavation is discharged from the opening of the tip of the excavating stable liquid discharge pipe toward the lower portion between the adjacent rotary cutters. The earth and sand produced by excavating the ground with a rotary cutter and the stable liquid for excavation are efficiently mixed, and the mixture of earth and sand and the stable liquid for excavation flows upward between adjacent rotary cutters. . At this time, the upward flow of the mixture of the earth and sand and the stable liquid for excavation is promoted by the flow of air injected from each injection hole of the air injection pipe or the air injection plate.
In addition, since the stabilizing liquid for discharging is discharged from the generating stable liquid discharge pipe to the part above the horizontal multi-axis rotary cutter and below the air injection pipe or the air injection plate, The stabilizing liquid does not float upward, and the mixture of the earth and sand and the excavating stabilizing liquid and the forming stabilizing liquid can be efficiently mixed, and a soil cement wall with good quality can be constructed.

  Further, in the present invention, each rotary cutter is provided with a plurality of blades, and in the excavation process, the earth and sand and the excavation stabilizing liquid are stirred and mixed by the blades of the rotary cutters, and the formation In the step, the earth and sand, the excavation stabilizing liquid, and the creation stabilizing liquid may be agitated and mixed.

  According to the method for constructing a soil cement wall of the present invention, a plurality of blades of a rotary cutter can stir and mix earth and sand and a stable liquid for excavation. Since the liquid can be mixed with stirring, a high-quality soil cement wall can be constructed efficiently.

  Furthermore, in the present invention, the plurality of blades may be provided so as to form a predetermined angle with respect to a circumferential direction of the rotary cutter.

  According to the method for constructing a soil cement wall of the present invention, it is possible to efficiently stir and mix earth and sand and the excavating stabilizer, and to efficiently stir the mixture of earth and sand and the excavating stabilizer and the stabilizing liquid. Can be mixed.

As described above, according to the construction how the soil cement wall of the present invention, a stabilizer for drilling and sand which is produced by drilling a ground and mixed efficiently, through between adjoining rotary cutter It can flow upwards. Therefore, the mixing of the earth and sand and the excavation stabilizing liquid does not become insufficient, and the abrasion of the cutter bid is not promoted by stirring the earth and sand as they are. In addition, since the mixture of earth and sand and the excavating stabilizer and the stabilizer can be efficiently mixed, a high-quality soil cement wall can be constructed. Furthermore, even if the ground is a geology containing viscous soil, it is possible to efficiently mix the excavated sediment and the excavating stabilizer, and to efficiently use the mixture of sediment and excavating stabilizer and the stabilizing stabilizer. Since the mixture can be mixed well, the clay soil does not adhere to the rotary cutter and the rotary cutter cannot be rotated, and the soil cement wall can be efficiently constructed.

It is explanatory drawing which showed one Embodiment of the construction method of the soil cement wall by this invention, Comprising: It is a schematic front view of the suspension type excavator used for construction of a soil cement wall. It is a side view of FIG. It is an enlarged view of the rotary cutter of FIG. It is an expanded sectional view of the rotary cutter of FIG. It is an expanded view of the drum of the rotary cutter of FIG. It is sectional drawing of the actuator for width direction attitude | position control, and the actuator for longitudinal direction attitude | position control, Comprising: It is explanatory drawing which showed the state which the casing shrunk | reduced. FIG. 7 is a plan view of the width direction posture control actuator and the longitudinal direction posture control actuator of FIG. 6. It is sectional drawing of the actuator for width direction attitude | position control, and the actuator for longitudinal direction attitude | position control, Comprising: It is explanatory drawing which showed the state which the casing extended. It is explanatory drawing which showed the excavation process of the soil cement wall. It is explanatory drawing which showed the relationship between the earth and sand of FIG. 9, and the stabilization liquid for excavation. It is explanatory drawing which showed the creation process of the soil cement wall. It is explanatory drawing which showed the relationship between the earth and sand of FIG. 11, and a creation stabilization liquid.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 12 show an embodiment of a method for constructing a soil cement wall according to the present invention. A method for constructing a soil cement wall according to the present embodiment uses a suspended excavator (hereinafter referred to as excavator 1) to excavate a groove 71 in the ground 70, and into the shape of the groove 71 in the excavated groove 71. A matching soil cement wall 75 is constructed.

As shown in FIGS. 1 and 2, the excavator 1 includes a frame 2 that is suspended from a wire 66 of a crawler crane (not shown), and a pair of rotary cutters 20 and 20 that are rotatably provided below the frame 2. And an attitude control device 40 that controls the attitude of the excavator 1.
In the present embodiment, the excavator 1 is provided with a pair of rotary cutters 20 provided at the lower part of the frame 2, but a plurality of rotary cutters 20 are provided at the lower part of the frame 2 in the horizontal direction, the vertical direction, and the like. The provided excavator 1 may be the target.

  The frame 2 has a rectangular parallelepiped shape formed by combining a plurality of steel materials vertically and horizontally, and a pair of hanging portions 8 are provided at both ends in the longitudinal direction on the upper surface 3 side. , 8 are suspended on the wire 66 of the crawler crane.

  At both ends in the longitudinal direction on the lower surface 5 side of the frame 2, a pair of rotary cutters 20, 20 are rotated so that the respective rotation axes are directed in the horizontal direction and are parallel to each other. It is provided freely. Both rotary cutters 20 and 20 are controlled in the direction of rotation in the direction of arrow a in FIG. 1 in order to allow the excavated earth and sand to be caught between the rotary cutters 20 and 20 from below.

  1 to 4, each rotary cutter 20 is integrally provided with a drive source (not shown), a drum 21 that is rotationally driven by the drive source, and a state protruding from the outer peripheral surface of the drum 21. A plurality of blades 22 and a cutter bit 30 provided above each blade 22 are configured.

  The drive source is, for example, a hydraulic motor (not shown), and is attached to the lower surface 5 side of the frame 2 so that the output shaft is horizontal and faces the width direction of the frame 2 (left-right direction in FIG. 2). A drum 21 is attached to the output shaft of the hydraulic motor.

  The hydraulic motor is connected to a hydraulic supply device (not shown) including a hydraulic pump installed on the ground via a hydraulic hose (not shown), and hydraulic pressure is supplied from the hydraulic supply device to the hydraulic motor via the hydraulic hose. By supplying, the rotary cutter 20 is rotationally driven integrally with the output shaft of the hydraulic motor.

  The drum 21 has a cylindrical shape with both ends closed, and is attached in a state in which the axis line coincides with the output shaft of the hydraulic motor. As shown in FIG. 2, a plurality of blades 22 and 22 ′ are provided in a plurality of rows (six rows in this embodiment) on the outer peripheral surface of the drum 21, and each blade row (first to sixth blade rows 31). To 36), cutter bits 30 are attached to the upper portions of the blades 22, 22 '.

  The first and sixth blade rows 31 and 36 are developed as shown in FIG. 5, and the plurality of plate-like blades 22 are arranged on the outer circumferential surface of the drum 21 so that the plate surface 23 is along the circumferential direction of the drum 21. The cutter bits 30 are respectively attached to the upper portions of the blades 22 so as to be integrally provided at a plurality of locations at predetermined intervals in the circumferential direction. FIG. 5 shows only the first blade row 31.

  As shown in FIG. 5, the second to fifth blade rows 32 to 35 include a plurality of blades 22 'formed in a shape obtained by bending a plate-like member from the center, At a predetermined interval in the circumferential direction on the outer peripheral surface of the drum 21 such that the plate surface 27 extends along the circumferential direction of the drum 21 and the plate surface 25 of the left half 24 forms a predetermined angle with respect to the circumferential direction of the drum 21. The cutter bits 30 are respectively attached to the upper part of the right half 26 of each blade 22 '. FIG. 5 shows only the second blade row 32 and the third blade row 33.

  In addition, each blade 22 ′ of the second to fifth blade rows 32 to 35 is not limited to the shape described above, but may be any shape that partially forms a predetermined angle with respect to the circumferential direction of the drum 21. In the present embodiment, as shown in FIG. 2, the plurality of blades 22 and 22 ′ are provided in six rows on the outer peripheral surface of the drum 21, but one or more rows may be provided.

  As shown in FIG. 1, while rotating both rotary cutters 20, 20 in the direction a in the figure, the crawler crane is operated to lower the frame 2, and the cutter bits 30 of both rotary cutters 20, 20 are placed on the ground 70. By making contact, the ground 70 can be excavated downward, and a groove 71 having a rectangular shape in plan view can be formed in the ground 70.

  As shown in FIGS. 1 to 3 and 9 to 12, the frame 2 has a pair of rotary cutters 20 and 20, when excavating a groove 71 in the ground 70, below the pair of rotary cutters 20 and 20. The excavating stabilizer supply pipe 13 for supplying the excavating stabilizer to the part, the creating stabilizer supplying pipe 16 for supplying the creating stabilizer to the upper part of the pair of rotary cutters 20, 20, and the creating stabilizer An air supply pipe 10 for supplying air to a portion above the supply position is provided.

  As shown in FIG. 10, the air supply pipe 10 is a compressor (one end connected to an air injection pipe 11 having a plurality of injection holes 12 provided horizontally at the lower end of the frame 2 and the other end installed on the ground. (Not shown). By supplying air to the air injection pipe 11 through the air supply pipe 10 by driving the compressor, air is injected upward from each injection hole 12 of the air injection pipe 11.

  In the present embodiment, one air injection pipe 11 is provided horizontally on the frame 2, but a plurality of air injection pipes 11 may be provided horizontally at the same height of the frame 2, or the frame One or a plurality of air injection pipes 11 may be provided in multiple stages at two different heights. Further, instead of the air injection pipe 11, a plate-like air injection plate (not shown) having a plurality of injection holes 12 may be used.

  As shown in FIGS. 1, 3, and 9 to 12, the excavating stabilizing liquid supply pipe 13 is provided along the vertical direction of the frame, and the upper end of the stabilizing liquid supplying apparatus (Fig. The lower end is connected to the excavating stable liquid discharge pipe 14 corresponding to each rotary cutter 20 below the frame 2.

  As shown in FIGS. 1 to 3, each of the excavating stable liquid discharge pipes 14 extends downward along the outer side of each rotary cutter 20 from the lower portion of the frame 2, and extends along the outer periphery of each rotary cutter 20. The tip is opened toward the lower part between the rotary cutters 20 and 20, and the lower end of the excavating stable liquid supply pipe 13 is connected to the upper end of each excavating stable liquid discharge pipe 14. Yes.

  In order to prevent sediment particles and the like from flowing into the excavating stable liquid discharge pipe 14 from the outside into the tip opening 15 of each excavating stable liquid discharge pipe 14, a valve such as an electromagnetic valve or a check valve (see FIG. Not shown).

  As shown in FIG. 9 and FIG. 10, a stable liquid for excavation (a mixture of bentonite and water, A mixture of a small amount of cement and the like) is discharged from the tip opening 15 of each excavating stable liquid discharge pipe 14 toward the lower part between the rotary cutters 20 and 20. Is done.

  As shown in FIGS. 1, 3, and 9 to 12, the forming stable liquid supply pipe 16 is provided along the vertical direction of the frame 2, and the stable liquid supply device (the upper end is installed on the ground) ( The lower end of the frame 2 is connected to a pair of forming constant solution discharge pipes 17 and 17 provided in a portion below the air jet pipe 10 at the lower end of the frame 2.

  As shown in FIGS. 1 and 2, each forming stable liquid discharge pipe 17 is provided horizontally at the lower end portion of the frame 2, and one end is opened toward an upper portion between the rotary cutters 20 and 20. The lower end of the forming stable liquid supply pipe 16 is connected to the other end of each forming stable liquid discharge pipe 17.

  In order to prevent dirt particles and the like from flowing into the stable liquid discharge pipe 17 from the outside into the tip opening 18 of each stable liquid discharge pipe 17, a valve such as an electromagnetic valve or a check valve (see FIG. Not shown).

  By supplying a stabilizing liquid (such as cement milk, which is a mixture of water and cement) from the stabilizing liquid supply device to the respective stabilizing liquid discharge pipes 17 via the stabilizing liquid supply pipes 16 for each forming, From the tip opening 18 of the stable liquid discharge pipe 17, the forming stable liquid is discharged from the horizontal direction to the upper portion between the rotary cutters 20 and 20.

  As shown in FIGS. 1 and 2, the attitude control device 40 controls the attitude of the frame 2 of the excavator 1 vertically so that the pair of rotary cutters 20, 20 at the lower part of the frame 2 is perpendicular to the ground 70. A width-direction posture control actuator 41 for controlling the posture of the frame 2 in the width direction; a longitudinal-direction posture control actuator 42 for controlling the posture of the frame 2 in the longitudinal direction; A drive source (not shown) for each actuator 41, 42 and an inclination angle detector (not shown) for detecting the inclination angle of the frame 2 of the excavator 1 are provided.

  In the present embodiment, a pair of width direction posture control actuators 41 and 41 are provided at both ends in the longitudinal direction of the lower end of the frame 2 so as to be extendable in the width direction of the frame 2 (the direction of arrow a in FIG. 2). Provided at both ends in the longitudinal direction of the upper end portion of the frame 2 is one longitudinal posture control actuator 42 that can extend and contract in the longitudinal direction of the frame 2 (the direction of arrow b in FIG. 1).

  Each of the width direction posture control actuators 41 is configured to be able to expand and contract outward from both outer surfaces 6 and 6 in the width direction of the frame 2, and these width direction posture control actuators 41 can extend in the width direction of the frame 2. Both outer surfaces 6, 6 are kept vertical.

  The longitudinal posture control actuator 42 is configured to be extendable outward from both outer surfaces 7, 7 in the longitudinal direction of the frame 2, and both the longitudinal posture control actuators 42 in the longitudinal direction of the frame 2 are configured. The outer surfaces 7, 7 are kept vertical.

  The width direction posture control actuator 41 and the longitudinal direction posture control actuator 42 have the same configuration, and are attached to the frame 2 as shown in FIGS. 6 to 8, and the outer surface 6 of the frame 2, 7 includes a casing 43 that can be expanded and contracted outward, and a jack 56 that is accommodated in the casing 43.

  The casing 43 is provided with a cylindrical inner casing 44 whose one end is closed by a substrate 45, and a cylindrical outer casing 46 whose one end is closed by a pressure contact plate 47 while being slidably provided on the outer peripheral surface of the inner casing 44. And a sealing member 53 that seals between the outer peripheral surface of the inner casing 44 and the inner peripheral surface of the outer casing 46.

  A sealed space 51 is formed inside the casing 43, and a jack 56 is accommodated in the space 51 so as to be extendable and contractible.

  The inner casing 44 of the casing 43 is configured such that a substrate 45 at one end is fixed to the frame 2 with a bolt or the like, and an outer casing 46 is slidable on the outer peripheral surface of the inner casing 44. Three annular grooves 52 are provided at intervals on the inner peripheral surface of the outer casing 46 on the other end side of the casing 43, and a U-shaped packing 54 is mounted in the two inner grooves 52. A dust seal 55 is mounted in the groove 52, and the seal member 53 is configured to seal between the outer peripheral surface of the inner casing 44 and the inner peripheral surface of the outer casing 46 by the U-shaped packing 54 and the dust seal 55.

  The jack 56 includes a cylinder 57 and a rod 58 that can protrude and retract from the cylinder 57, the cylinder 57 is fixed to the inner surface of the substrate 45 of the inner casing 44 by a bolt, and the tip 59 of the rod 58 is a pressure contact plate of the outer casing 46. It is attached to the inner surface of 47 so as to be rotatable relative to the press contact plate 47.

  In the present embodiment, the inner plate 49 is rotatably attached to the tip of the rod 58 of the jack 56 by the fixing screw 61, and the circular head 62 of the fixing screw 61 is provided at the center of the inner surface of the press contact plate 47. The inner plate 49 is fixed to the inner surface side of the pressure contact plate 47 with a bolt 65 in such a manner that the tip end 59 of the rod 56 of the jack 56 is relative to the pressure contact plate 47. It is attached so that it can rotate freely.

  The drive source (not shown) is composed of a hydraulic pressure supply device such as a hydraulic pump that supplies hydraulic pressure to the jacks 56 of the width direction posture control actuators 41 and the longitudinal direction posture control actuators 42. The width direction posture control actuator 41 and the jack 56 of each longitudinal direction posture control actuator 42 are connected to a hydraulic pressure supply device installed on the ground or the like via a hydraulic hose or the like. By supplying hydraulic pressure to the jacks 56 of each width direction posture control actuator 41 and each longitudinal direction posture control actuator 42 from a hydraulic supply device via a hydraulic hose or the like, each width direction posture control is performed via each jack 56. Actuator 41 and each longitudinal direction attitude control actuator 42 expand and contract.

  1 and 2, any one of the width direction posture control actuators 41 or any one of the longitudinal direction posture control actuators 42 is expanded and contracted, and the outer surface of the pressure contact plate 47 is brought into pressure contact with the inner surface of the excavated groove 71. Thus, the outer surfaces 6 and 7 in the width direction and the longitudinal direction of the frame 2 can be kept vertical, and the grooves 71 can be vertically excavated in the ground 70 by the pair of rotary cutters 20 and 20 at the lower part of the frame 2.

  In the present embodiment, a pair of width direction posture control actuators 41 and 41 are provided at both ends in the longitudinal direction of the lower end portion of the frame 2, but both end portions in the longitudinal direction of the upper end portion of the frame 2. Also, a pair of width direction posture control actuators 41, 41 may be provided. Also, one longitudinal direction attitude control actuator 42 is provided at each longitudinal end of the upper end of the frame 2, but one longitudinal orientation control is also provided at both longitudinal ends of the lower end of the frame 2. An actuator 42 may be provided.

  In order to construct the soil cement wall 75 on the ground 70 using the excavator 1 and the attitude control device 40 configured as described above, first, as shown in FIGS. 9 and 10, both rotary cutters 20 of the excavator 1 are used. , 20, and the crawler crane is operated to lower the excavator 1, and both rotary cutters 20, 20 are brought into contact with the ground 70, so that the ground 70 is excavated downward and the ground 70 is viewed in plan view. A rectangular groove 71 having a predetermined depth is formed.

  At this time, the excavating stable liquid is supplied to the excavating stable liquid discharge pipe 14 from the above-mentioned stable liquid supplying apparatus via the excavating stable liquid supply pipe 13, and the excavating stable liquid is supplied to the excavating stable liquid discharging pipe 14. It discharges toward the downward part between both rotary cutters 20 and 20 from the front-end | tip opening 15. FIG. Thereby, the earth and sand excavated by both rotary cutters 20 and 20 and the stable liquid for excavation can be mixed, and it can be wound between both rotary cutters 20 and 20. Moreover, the first and sixth blade rows 31 and 36 of each rotary cutter 20 and the bent blades 22 'of the second to fifth blade rows 32 to 35 are efficiently used for the earth and sand and the stable liquid for excavation. Since it can stir well, the load of the rotary cutters 20 and 20 can be reduced, wear of the cutter bid 30 can be reduced, and adhesion of earth and sand around each rotary cutter 20 can be prevented.

Moreover, air is supplied to the air injection pipe 11 from the compressor on the ground through the air supply pipe 10, and the air is injected upward from each injection hole 12 of the air injection pipe 11. Thereby, since the upward flow of the mixture of the earth and sand caught between the rotary cutters 20 and 20 and the stabilizing liquid for excavation can be promoted, the excavated earth and sand can be efficiently discharged from the excavation surface. The excavation speed can be improved.

  In the process of excavating the groove 71 in the ground 70, the inclination angle detector of the attitude control device 40 detects the inclination angle of the frame 2 of the excavator 1 one by one, and based on the detected data, any width direction The frame 2 of the excavator 1 is configured by expanding or contracting the attitude control actuator 41 or any of the longitudinal direction attitude control actuators 42 and bringing the outer surface of the pressure contact plate 47 into pressure contact with the inner surfaces 72 and 73 of the excavated groove 71. In this state, a groove 71 is excavated vertically in the ground 70.

  Then, after the excavation of the groove 71 is completed, as shown in FIG. 11 and FIG. 12, the stable liquid for excavation is switched to the stable liquid for formation, and the stable liquid supply device on the ground passes through the stable liquid supply pipe 16 for formation. The stabilizing liquid is supplied to the forming stable liquid discharge pipe 17, and the forming stable liquid is applied from the front end opening 18 of the forming stable liquid discharging pipe 17 to the upper portion between the rotary cutters 20 and 20 from the horizontal direction. The excavator 1 is pulled up from the inside of the groove 71 by operating the crawler crane while discharging and injecting air from each injection hole 12 of the air injection pipe 11 as necessary.

As a result, the mixture of earth and sand and the stabilizing liquid for excavation and the stabilizing liquid for creation, which are caught between the rotary cutters 20 and 20 and whose upward flow is promoted by air, are stirred and mixed. Agitation is promoted by the blades 22 and 22 ′ of the blade rows 31 to 36 of the rotary cutter 20, and a soil cement wall 75 in which the earth and sand, the excavating stabilizer, and the forming stabilizer are uniformly agitated and mixed is formed in the groove 71. Built.
In addition, by putting the stabilizing liquid in the upper part of the rotary cutters 20, 20, the stabilizing liquid is stirred by the rotary cutters 20, 20, and below the rotary cutters 20, 20 (to the cavities by lifting the excavator 1). Therefore, a high-quality soil cement wall 75 can be constructed.

  In this case, the creation stabilizing liquid is discharged to the upper part of the rotary cutters 20 and 20, and air is jetted as necessary from the part above the discharge position of the building stabilization liquid upward. Therefore, the stabilizing liquid does not float upward due to the flow of air before it is mixed with the mixture of earth and sand and the excavating stabilizer. It can be mixed uniformly and a high quality soil cement wall 75 can be constructed.

  In the construction method of the soil cement wall of the present embodiment configured as described above, the tip of the excavating stable liquid discharge pipe 14 is opened toward the lower part of the rotary cutters 20 and 20, Since the excavation stabilizing liquid is discharged from the tip opening 15 toward the lower part between the rotary cutters 20 and 20, the earth and sand produced by excavating the ground 70 by the rotary cutters 20 and 20 and The excavating stabilizer can be efficiently mixed, and the mixture of the earth and sand and the excavating stabilizer can be wound between the rotary cutters 20 and 20 and flow upward. Moreover, at this time, since the earth and sand and the stable liquid for excavation can be efficiently stirred and mixed by the blades 22 and 22 'of each rotary cutter 20, the load on both rotary cutters 20 and 20 can be reduced. Wear of both rotary cutters 20 and 20 can be reduced.

  Further, the tip of the stabilizing liquid discharge pipe 17 is opened at the upper part between the rotary cutters 20 and 20, and the stabilizing liquid for forming is supplied from the tip opening 18 toward the upper part of the rotary cutters 20 and 20. Since the air injection pipe 11 is horizontally provided in the upper part of the stable liquid discharge pipe 17 for creation and air is jetted upward from each injection hole 12, the ground 70 is excavated. In this case, the upward flow of the mixture of earth and sand and the excavation stabilizing liquid can be promoted by the air flow. Further, when the soil cement wall 75 is formed, the excavator 1 is lifted, so that air is not mixed with the forming stable liquid, and the forming stable liquid is not lifted upward. In addition, since the stabilizing liquid, the earth and sand, and the excavating stable liquid can be uniformly stirred and mixed by the blades 22 and 22 ′ of each rotary cutter 20, a high-quality soil cement wall 75 can be constructed. .

  In the above description, the excavator 1 is suspended from the crawler crane. However, the excavator 1 may be suspended or suspended from the suspension machine.

DESCRIPTION OF SYMBOLS 1 Suspended excavator 2 Frame 3 Upper surface 5 Lower surface 6 Outer surface (width direction) 7 Outer surface (longitudinal direction)
DESCRIPTION OF SYMBOLS 8 Suspension part 10 Air supply pipe 11 Air injection pipe 12 Injection hole 13 Stable liquid supply pipe for excavation 14 Stabilization liquid discharge pipe 15 for excavation 15 Front opening 16 Stabilization liquid supply pipe for creation 17 Stabilization liquid discharge pipe for creation 18 End opening 20 Rotary Cutter 21 Drum 22 Blade 22 'Blade 23 Plate surface 24 Left half 25 Plate surface 26 Right half 27 Plate surface 30 Cutter bit 31 First blade row 32 Second blade row 33 Third blade row 34 Fourth blade row 35 First 5 blade row 36 6th blade row 40 posture control device 41 actuator for width direction posture control 42 actuator for longitudinal direction posture control 43 casing 44 inner casing 45 substrate 46 outer casing 47 pressure contact plate 48 recess 49 inner plate 51 space 52 groove 53 seal Member 54 U-shaped packing 55 Dust seal 5 Jacking 57 cylinder 58 rod 59 tip 61 fixing screw 62 head 65 bolt 66 wire 70 ground 71 groove 72 width direction of the inner surface 73 longitudinally of the inner surface 75 soil cement wall

Claims (4)

A method for constructing a soil cement wall by a suspended excavator provided with a horizontal multi-axis rotary cutter at the bottom of the frame,
While lowering the suspended excavator, the horizontal multi-axis rotary cutter of the suspended excavator is rotated to excavate a groove in the ground, and the excavated earth and sand are raised between the adjacent rotary cutters, In this case, the stabilizing liquid for excavation is discharged to the lower part of the horizontal multi-axis rotary cutter and mixed with the excavated earth and sand, and air is injected from the upper part of the horizontal multi-axis rotary cutter. An excavation step for promoting upward flow of the mixture that has risen between the adjacent rotary cutters;
Raise the suspension excavator, discharge the stabilizing liquid above the plurality of rotary cutters to a portion below the portion that injects the air, and rises between the adjacent rotary cutters A method for constructing a soil cement wall, comprising: a forming step of stirring and mixing the mixture and the forming stabilizing liquid. The excavation stabilizing liquid is bent along the outer periphery of each rotary cutter, and the tip of the excavation stabilizing liquid discharge pipe opened toward the lower portion between the adjacent rotary cutters. Discharged,
The air is provided at least in one stage horizontally above the horizontal multi-axis rotary cutter, and each of the air injection plates having a plurality of injection holes or the air injection plates having a plurality of injection holes. Injected from the injection hole,
The forming stable liquid is formed above the horizontal multi-axis rotary cutter, from the forming stable liquid discharge pipe provided in the lower part of the air injection pipe or the air injection plate, to the adjacent rotary cutter. 2. The method for constructing a soil cement wall according to claim 1, wherein the soil cement wall is discharged toward an upper portion therebetween.   Each rotary cutter is provided with a plurality of blades, and in the excavation step, the earth and sand and the stable liquid for excavation are stirred and mixed by each blade of each rotary cutter, and in the creation step, The method for constructing a soil cement wall according to claim 1 or 2, wherein the excavation stabilizing liquid and the creation stabilizing liquid are stirred and mixed.   The method for constructing a soil cement wall according to claim 3, wherein the plurality of blades are provided so as to form a predetermined angle with respect to a circumferential direction of the rotary cutter.

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