JP3446127B2 - Drain pile creation device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for forming a strong drain pile in soft ground on land without noise. 2. Description of the Related Art Generally, when a drain pile is formed on soft ground on land, it is necessary to consider the influence on the neighborhood and to make noiseless
A non-vibrating auger machine is used, which is a soil improvement material such as sand and crushed stone which is introduced into the soft ground after rotating into a hollow ground provided with a spiral blade on the outer peripheral surface while rotating the hollow pipe. (Drain material) is discharged into the ground at the same time as the hollow tube is pulled out. [0003] However, in this method, when the improving material in the hollow tube is discharged into the ground from the lower end of the tube, the discharge may not be performed well due to frictional resistance with the inner peripheral surface of the hollow tube.
For this reason, compressed air is blown into the hollow tube to forcibly discharge the improved material while pressing the upper surface of the improved material. However, in any case, when a hollow pipe is driven by using a vibro hammer as in the construction of a drain pile on the sea where it is not necessary to consider vibration, noise, etc., the vibration from the vibro hammer is required. The improvement material can be compacted to some extent by transmission, but in the construction of drain piles on land by the auger-type vibration-free construction method, there are many gaps between the discharged improvement materials, and Even if the pile diameter of the drain pile immediately after being constructed satisfies the specified value, if the residual air in the pile decreases due to the lateral earth pressure under the ground, the pile diameter decreases significantly, and the effective circular permeability radius Becomes narrower, and in some cases, it may be necessary to reconsider the spacing between the piles and review the load. [0005] Further, since the improved material discharged into the ground is not properly compacted, a large amount of fine-grained soil in the smear zone near the peripheral surface of the formed drain pile is taken into the formed pile, and the consolidation settlement later occurs. Even if loading embankment is added for promotion, drainage efficiency of excess pore water in soft ground will be deteriorated. SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems in the conventional auger-type drain pile construction method on land and reduces the gap between the improved materials forming the pile. Therefore, the present invention proposes a device that can maintain a strong and planned drain pile diameter. According to the present invention, a long rod which can be moved up and down by a cylinder is hung down on the axis of a hollow pipe for drain pile formation, and a horizontal vibration is applied to the lower end of the rod. At the lower end of the hollow pipe, a split open / close lid that forms an inverted cone is attached.When the hollow pipe penetrates into the ground, the open / close lid is closed, and the hollow pipe is pulled out to improve the material underground. When discharging to the soft soil, the rod is lowered and the open / close lid is forcibly expanded by the arm ring attached below the rod, and the vibrator is protruded from the lower end of the hollow pipe and vibrated, so that the soft ground is released. The discharged improvement material is compacted while moving it slightly to the side to create a strong drain pile having a predetermined diameter. Less than,
An embodiment of the present invention will be described with reference to the drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference numeral 1 denotes a drain pile forming hollow pipe (casing pipe) provided with a spiral blade 2 on a lower outer periphery. A swivel mechanism 3 is provided at one end of the hollow pipe. Is equipped with an auger machine 4 and two motors 5 of the machine 4
Only the hollow tube 1 is rotatable in its circumferential direction. Reference numeral 6 denotes an open / close lid divided vertically into two or three pivotally pivotally supported at the lower end of the hollow tube 1. The open / close lids 6 have a substantially inverted conical shape when they are swiveled against each other and closed. Is configured. A spiral blade 2a connected to the spiral blade 2 below the hollow tube 1 when the lid 6 is closed is also formed on the outer surface of the opening / closing lid 6. Reference numeral 7 denotes a communication pipe installed on the upper side of the auger machine 4. The communication pipe 7 has the same axis as the lower hollow pipe 1 and has substantially the same diameter as the hollow pipe 1. Mechanism 3
Are in communication with each other. A hopper 8 for charging an improved material with a check valve 18 is attached to the upper side of the communication pipe 7, and a downward cylinder 9 is fixed to the upper inner shaft portion. A long pipe rod 10 reaching the position of the opening / closing lid 6 is vertically provided, and the cylinder 9 can be moved up and down within the hollow tube 1 by a predetermined distance. An electric vibrator 11 which vibrates in the horizontal direction is fixed to the lower end of the pipe rod 10 and the outer diameter of the rod 10 slightly above the vibrator 11 is substantially equal to the inner diameter of the hollow tube 1. When the cylinder 9 moves forward and the rod 10 descends, the arm ring 12 is attached, and the opening / closing lid 6 in which the arm ring 12 is closed is forcibly pushed open from the inside thereof, and at the same time, the vibrator at the lower end is opened. 11 protrudes downward from the lower end of the opening / closing lid 6. Reference numeral 13 denotes a projection integrally formed at the upper end of the opening / closing lid 6 so as to slightly project through a small slot (not shown) formed in the wall of the hollow tube 1 when the opening / closing lid 6 is expanded. The arm ring 1 is moved by the lever 9
2 rises, the lever 1 projecting into the hollow tube 1
The opening / closing lid 6 that has been expanded by pressing against the opening 3 is forcibly closed to form an entire inverted cone. A compressed air blowing port 14 is provided at the upper end of the pipe rod 10, and a plurality of compressed air blowing ports are provided at appropriate intervals vertically above and below the arm ring 12 below the rod 10. The outlet 15 is provided downward, and forcibly discharges the improving material such as sand charged into the hollow tube 1. Thus, the entire apparatus shown in the drawing is constructed such that its head end is hung by a wire and can be moved up and down by a winch along a guide leader (not shown) arranged upright on the side. After positioning the tip of the opening / closing lid 6 closed in the shape of an inverted cone as described above at a predetermined position of the soft ground 16 to be improved, the auger machine 4 is operated to rotate only the lower hollow tube 1. Because of that, they penetrate the ground without noise and vibration. At this time, the cylinder 9 in the upper communication pipe 7
The arm ring 12 is pressed against the projecting lever 13 of the opening / closing lid 6 to pivot the opening / closing lid 6 in the closing direction, and the opening / closing lid 6 is firmly moved by the earth pressure accompanying penetration into the ground. Hollow tube 1 of soft soil when closed and penetrated
Inflow into the interior is prevented (see FIG. 4). When the hollow tube 1 reaches a predetermined depth of the ground 16, a predetermined amount of an improved material 17 such as sand or crushed stone is charged from the hopper 8 into the hollow tube 1 or, as shown in FIG. Put one or several doses of quantification,
First, the piston 9 is actuated to lower the pipe rod 10, the opening / closing lid 6 closed by the arm ring 12 below the rod 10 is expanded, and while the hollow tube 1 is pulled out by a predetermined length, the improving material 17 is passed through the hollow tube. 1. While discharging from the lower end, the vibrator 11 at the lower end is operated to compact the discharged improving material 17 in the horizontal direction (see FIG. 5). When the improvement material 17 is discharged by pulling out the hollow tube 1, compressed air is blown into the upper portion of the hollow tube 1 to pressurize the upper surface of the improvement material 17 of the tube 1, and a compressed air blowing port above the pipe rod 10. Compressed air is supplied from 14 and spouted from the lower outlet to promote discharge of the improving material 17 out of the pipe 1. When the hollow tube 1 is pulled out from the soft ground 16 for a predetermined length in this way, the drawing is stopped once, the air supply to the pipe rod 10 is stopped while the opening / closing lid 6 is opened, and the hollow tube 1 is pulled out. The compressed air in the inside is also exhausted from the exhaust port 19 provided in the communication pipe 7 and again a predetermined amount of the improving material 17 is discharged.
, And the same operation as above is performed to perform hollow tube 1
Is extracted and the improving material 17 is discharged. Then, the hollow pipe 1 is sequentially pulled out from the soft ground 16 while repeating the above operation (see FIG. 6), and finally, the improving material 17 is formed in the ground 16 in a tightly compacted state. The drain pile 20 is created. Furthermore, the improvement material 17 discharged from the lower end of the hollow tube 1 is tightly compacted with the horizontal pile by the vibrator 11 so that the drain piles 20 are compacted. The fine particles of the soft soil in the smear zone near the outer peripheral surface are less likely to be sucked into the pile 20, and the efficiency of absorbing water from the soft soil is also good. According to the present invention, as described above, when the hollow tube penetrates into the soft ground by driving the cylinder, the opening / closing lid at the lower end of the hollow tube is forcibly closed in an inverted conical shape. At the same time, when the improvement material is discharged to the ground, the opening / closing lid expands reliably, so that a drain pile with a specified pile diameter can be created. Since the improved material discharged from the lower end of the hollow tube as described above is not compacted by the vibrator at the lower end of the pipe rod,
It is possible to construct a strong drain pile with good water absorption efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall explanatory view of a drain pile forming apparatus according to the present invention. FIG. 2 is an explanatory perspective view of a lower end portion of a hollow pipe in the drain pile forming device according to the present invention, showing a state when a lower end opening / closing lid is closed. FIG. 3 is an explanatory perspective view of a lower end portion of a hollow pipe in the drain pile forming device according to the present invention, showing a state where a lower end opening / closing lid is opened. FIG. 4 is a view showing one process in a method for forming a drain pile according to the present invention, and shows a state where a hollow pipe has penetrated to a predetermined depth. FIG. 5 is a view showing one process in a method for forming a drain pile according to the present invention, and shows a state where pulling out of a hollow tube from soft ground is started. FIG. 6 is a view showing one process in a method for forming a drain pile according to the present invention, and shows a state where the drain pile is being formed. [Description of Signs] 1-Hollow tube for drain pile formation 2-Spiral blade 3-Swivel mechanism 4-Auger machine 5-Motor 6-Opening / closing lid 7-Communication tube 8-Hopper 9-Cylinder 10-Pipe rod 11-Vibrator 12-arm ring 13-projection lever 14-compressed air inlet 15-compressed air outlet 16-soft ground 17-improvement material 18-check valve 19-exhaust port 20-drain pile

Claims (1)

(57) [Claim 1] A spiral blade is formed on the outer peripheral surface, and an inverted cone is formed at the lower end of a drain pile forming hollow tube which is rotated in a circumferential direction by an auger machine when closed. A split opening / closing lid is pivotally attached, and a communication pipe having the same axis as the hollow pipe and communicating with the hollow pipe is provided at the head of the hollow pipe via a swivel mechanism of the auger machine. A downward cylinder is fixed to the axial center of the communication pipe, and a pipe rod whose lower end reaches the opening / closing lid position is vertically provided at the piston rod tip, and a vibrator that vibrates horizontally is attached to the lower end of the pipe rod. An arm ring having an outer diameter substantially equal to the inner diameter of the hollow pipe is fixed to a position slightly above the vibrator of the pipe rod, and the arm ring is slightly inserted into the hollow pipe at the upper end of the opening / closing lid by raising the pipe rod. Protrusion The opening / closing lid is forcibly closed by pressing against a projection lever integrally formed as described above, and the opening / closing lid is forcibly expanded by pressing the opening / closing lid from the inside thereof by descending the pipe rod. A drain pile forming apparatus characterized by the above-mentioned.