JPS58185826A - Construction of foundation pile - Google Patents

Abstract

PURPOSE:To construct a foundation pile having a large frictional force by a method in which excavation is performed while improving the ground by an excavation mechanism penetrated into a round hollow pile, and at the same time the pile is settled to a supporting layer by means of a penetrator. CONSTITUTION:An excavating shaft 1 provided with an excavating blade 2 which can be freely opened or closed and a stirring blade 3, penetrated into the hollow of a foundation pile 5, is rotationally penetrated by an excavating penetrator 8, and an improving agent, e.g., cement milk, etc., is charged and mixed through a fluid pathway provided in the center of the shaft 1 to improve the ground till a supporting layer 4. Then, the shaft 1 is pulled up while being turned inversely, the pile 5 is settled to the supporting layer 4 by an oil-pressure cylinder 6, and the ground 11 to be improved is solidified to complete all the construction area. By this, a great bearing force can be provided for the pile 5 because the friction coefficient between the periphery bonded with solidified improved soil of the pile 5 and the ground is made larger.

Description

[Detailed Description of the Invention] This invention improves the ground by mixing and stirring the excavated soil and soil improvement material of the ground where the piles are to be constructed, and improves the quality of steel pipe piles, concrete piles, etc.
Concerning the construction method of foundation piles in which steel pipe concrete piles, etc. are sunk using an excavation press-in device or an excavation vibration press-in device equipped with a high-frequency vibrator, etc. In general, foundation piles such as steel pipe υ1, concrete piles, steel pipe concrete piles, etc. Do you use a diesel hammer, hydraulic hammer, Monken, etc. to drive the pile head? If construction is to be carried out in a construction area or near a city area, use a construction method that produces less noise, such as the medium digging method, by sinking piles, and using cement milk to create a bulb at the tip of the pile and support the pile. The fc is firmly supported by the layer. However, although the above-mentioned medium excavation method has a support effect FiM due to the bulb at the tip, it is a method in which the screw auger inserted into the hollow part of the pile is rotated and soil is pressed in while removing soil, so the pile and the surrounding ground are The shoreline was small, and there was little so-called ``familiarity'' with the surrounding ground.

This invention was made in view of such circumstances.
At the location where foundation piles such as steel pipe piles, concrete piles, and steel pipe concrete piles are to be constructed, the ground is improved by deep mixing to a depth of 12 times larger than the pile (Y), and at the same time, the foundation trT, ?, is to be constructed. By sinking down to support N1 using a press-in device or a lifting press-in device with a high-frequency vibrator added to the press-in device, there is less noise and vibration.
The purpose of the present invention is to provide a method for constructing base piles that have a high frictional force and have good compatibility with the ground, and will be described in detail below with reference to FIGS. 1 to 6.

Figures 1 to 5 are explanatory drawings showing one embodiment of the present invention. Figure 1 shows the process immediately after the start of elliptical construction, and shows the process of opening and closing the workpiece inserted in advance into the hollow part of the pile. The excavation shaft 1 equipped with the excavation blades 2 and the stirring blades 3 is inserted into a predetermined excavation press-fitting device w.
At t8, the excavation is carried out by rotation, and an improvement material such as cement milk is filled through the fluid passage provided in the hollow part of the excavation shaft 1, and while stirring and mixing, the ground is improved to the support 114 or to a predetermined depth as shown in FIG. At the same time, hydraulic cylinder 6
The foundation piles 5 are laid down. Next, as shown in FIG. 3, after the ground has been improved to the support layer 4 or a predetermined depth 1, the excavation shaft 1f is sunk into the foundation pile 5 while being reversed and pulled up to the support layer 4 or a predetermined depth. Next, as shown in Fig. 4, the excavation shaft 1 is pulled out while being reversed.
If necessary, a ground improvement material such as cement milk is filled during lifting, and the excavation shaft 1 is pulled up while mixing and stirring. As shown in FIG. 5, the ground is improved until the tip of the foundation pile 5 reaches the support layer 4 or a predetermined depth 1 [1], and the foundation pile 5 is completely sunk, and when the soil improvement part 11 is solidified, the weave 1 is completed. Other real examples of
An excavation vibration press-in device 9f is used in which a high-frequency vibrator 7 is added to the excavation press-in device 8 shown in the figure as shown in FIG.
When the foundation pile 5 is rotated and excavated, the foundation pile 5 is vibrated by the high-frequency vibrator 7 and press-fitted by the hydraulic cylinder 6.As explained above in detail, the construction method of the present invention has the following effect 4. (a) The soil and the soil improvement part by deep mixing are integrated (steel pipe piles, concrete piles, steel pipe concrete piles, etc.), the soil improved by the soil adheres well to the outside, and the outer periphery of the solidified ground improvement part and There is a so-called "familiarity" with the ground.
By having a good friction coefficient, the coefficient of friction with the ground is large, so the pile can obtain a large bearing capacity.

(b) Since the ground at the tip of the pile is not disturbed, a large support capacity for the tip of the pile can be obtained.

(c) Since the foundation pile is surrounded by a solidified ground improvement section, it is possible to obtain piles that are less likely to buckle.

2) Since the area where the piles will be constructed is deep mixed ground improved in advance, the vibrations generated when the piles are sunk will not be transmitted to the surrounding ground using a high wave vibrator, and the vibrations caused by the impact of the pile caps will not be transmitted to the surrounding ground. In the consolidated layer area where negative friction is expected to occur, the piles were dug using only water, 614 liters of agitation, and the piles were sunk, without using soil improvement materials such as cement milk. , VC between the ground and the pile
It will be possible to reduce the friction that occurs (to) Since there is almost no soil removed, there is no need to dispose of the remaining soil0

[Brief explanation of drawings]

Figures 1 to 5 are explanatory diagrams showing one embodiment of the foundation pile construction method according to the present invention. Fig. 3 shows the process of filling the ground improvement material and sinking the pile while mixing and agitating the pile. Step 4:
The figure shows the process of pulling up the excavation shaft, and Fig. 5 shows the state after construction is completed. Fig. 6 shows the excavation vibration press-in device used in another embodiment of this invention. ...Drilling blade, 3...Agitation blade, 4
...Support layer, 5.Foundation pile, 6.Hydraulic cylinder, 7.High frequency vibrator, 8.Drilling press-in device, 9.
...Horimichi vibration press-in device, 11...Ground improvement department. Tokukin Izuruhito Tenox Co., Ltd. Agent Patent Attorney Hideaki Sato Pu 3□ □ 1 H127-l Leah] 6

Claims (1)

[Claims] Excavation wings that can be expanded and contracted inserted into the hollow part of circular hollow piles such as steel pipe piles, concrete piles, and steel pipe concrete piles.
Using an excavation mechanism equipped with stirring blades, a soil improvement material such as cement milk is filled and stirred while excavating to a size slightly larger than the diameter of the foundation pile, up to the supporting layer of the ground where the foundation pile is to be worked, or to a predetermined depth. A foundation pile construction method 9, characterized in that, while improving the ground, the piles are simultaneously sunk to a supporting layer or a predetermined depth using a press-in device or a vibratory press-in device equipped with a high-frequency vibrator.