JPS62202118A - Burying work of pile - Google Patents

Abstract

PURPOSE:To obtain a foundation pile well fixed to an excavated pit in a short time by a method in which rich-mixed cement milk is injected into an excavated pit with mud water, and a hollow pile is settled into the pit under its own weight. CONSTITUTION:While the ground is excavated by a rotary rod auger 5 with stirring, pressure water is jetted from the tip of the auger 5 to form an excavated pit Ha with mud water in a place where a pile is to be buried. Rich-mixed milk C is injected into the bearing layer on the lower end of the pit Ha from tip of the auger 5 and the auger 5 is gradually pulled up to the ground's surface. A hollow pile 8 is settled into the pit Ha under its own weight, and the upper end of the pile 8 is fixed to the upper part of the pit Ha by a supporting steel plate 8b. The pile foundation which can be well fixed to the excavated pit can thus be constructed in a short time.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a method for excavating and burying piles.

(Prior art) Conventionally, there have been methods for burying concrete piles, steel pipe piles, etc. for building foundations, such as the driving method and the vibration method, but in recent years the excavation insertion method has become the most popular from the perspective of preventing vibration pollution. It is widely adopted. That is, this excavation and insertion method is a method in which a hole is formed in a predetermined ground using a rod auger, and a concrete pile or the like is deposited under its own weight into the hole.

In order to implement this construction method, various efforts have been made and various devices have been proposed, but each has its advantages and disadvantages.
Various problems had been raised in terms of work time and the support capacity of the tip of the pile to be buried.

(Means for Solving the Problems) The present invention can shorten the working time required for the process in the pile excavation and insertion method, and improves the excavation and agitation of the excavated earth and sand, so that the piles to be inserted are The purpose of this project is to provide a method for embedding piles in an excavated hole that has good solidification properties. Pressurized water is injected from the tip of the rod auger while excavating and stirring the soil, turning the excavated soil into mud, creating an excavation hole filled with muddy water of a predetermined depth at the site where the pile is planned to be buried, and at the bottom end of the excavation hole. Inject a richly blended root hardening solution into the supporting layer from the tip of the rod auger, and use the rod auger to stir the soil and root hardening liquid in the supporting layer to form soil cement-like root hardening in the supporting layer. After allowing the bulb to be constructed, the rod auger is pulled up from the excavated hole while extracting the pile circumferential fixing liquid from the tip of the rod auger, and then the hollow pile having a support iron plate on the upper end surface is allowed to sink under its own weight into the excavated hole. , by rotating the pile, the lower end of the pile is fitted into and integrated with the root hardening bulb, and the upper end of the pile is fixed in the upper part of the excavation hole through support. This is a method for burying piles.

(Function) In the pile burying method of the present invention, first, an excavation hole is dug to a predetermined depth in the planned pile burying site, and a cylindrical hole having a plate-like stirring blade and a helical spiral screw on the outer wall surface is formed. As the rod auger rotates, the earth and sand in the excavated hole are dug upward by a spiral screw, and the plate-shaped stirring blades break up the earth and sand aggregates. It can be crushed and stirred. In other words, the stirring blades and spiral screws of this rod auger are formed alternately in the longitudinal direction of the rod auger, and due to the synergistic action of the spiral screws and stirring blades, the excavated soil is moved vertically and agitated. Destroyed. In addition, since pressurized water is injected from the tip of the rod auger during the excavation process, during the process of drilling the excavation hole, the agitated earth and sand are stirred and kneaded together with the injected water to become mud. Since this mud presses against the wall of the excavated hole, the excavated hole is prevented from collapsing and can be effectively excavated to a predetermined depth.

In other words, in the past, excavated holes were dug using a rod auger that had either a stirring blade or a spiral screw, so in order to improve the effect of stirring the earth and sand in the excavated hole, the rod auger was repeatedly moved in the vertical direction during excavation. However, since the rod auger of the present invention has excellent stirring ability, there is no need to repeatedly move it up and down. In this way, an excavation hole filled with muddy water is formed with a rod auger, and after reaching a predetermined depth, a rich root solidifying solution with a high cement content is applied from the tip of the rod auger to support the bottom end of the excavation hole. Can be injected completely into the layer. This injected root hardening solution is mixed with the soil and sand in the support layer using a rod auger, and as a result, the root solidification solution and the soil in the support layer are mixed together and form cement-like roots. Solid bulbs can be established.

Furthermore, in the process of pulling up the rod auger, a pile circumference fixing solution having a poorer composition than the root solidifying solution is poured out from the tip of the rod auger. This pile circumferential fixing fluid also mixes moderately with the mud in the excavated hole.

After the rod auger is pulled up from inside the excavated hole, piles such as concrete piles can be sunk into the excavated hole from above by their own weight.

Since the pile in the present invention has an outwardly protruding support iron plate fixed to its upper end surface, the pile is suspended through this support iron plate and is rotated so as to be inserted into the root hardening bulb in the support layer. By inserting the lower end, the hardening bulb and the lower end of the pile are integrated, and the lower end of the pile is firmly supported by the hardening bulb, increasing the support capacity of the tip of the pile. Further, since the supporting iron plate fixed to the upper end surface of the pile is fitted into the hole wall at the upper part of the excavated hole and fixed to the hole wall, the pile is prevented from sinking more than necessary. Therefore, the pile is secured in the excavation hole with its lower end maintained in the correct position within the hardening bulb.

(Example) Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows an apparatus for carrying out the pile burying method of the present invention, in which a wire 3 is hung from a tower 2 of an excavator 1, and an auger motor 4 is connected to this wire 3. A rod auger 5 is suspended from the lower end of the auger motor 4 in a hanging manner. In addition, this rod auger 5 is formed in a hollow shape, and the rod auger 5
A root solidifying liquid such as water or cement milk is pumped into the hollow portion from an external grouting device 6 through a grouting hose 7.

The details of this rod auger 5 will be explained in the second [ffl]. The rod auger 5 used in the present invention is formed in a hollow cylindrical shape, and has a spiral spiral screw 5a on its outer wall and a rotation of the rod auger 5. A plate-shaped forward stirring blade 5b that is oriented in the direction and protrudes outward, and a reverse stirring blade 5c that is oriented in the opposite direction to the rotational direction of the rod auger 5 are fixed in a protruding manner.

This spiral screw 5a and the forward stirring blade 5b
The and counter-direction stirring blades 5c are arranged alternately at regular intervals along the longitudinal direction on the outer wall of the rod auger 5, and the number and arrangement state thereof depends on the length of the rod auger used, etc. There are differences. Further, generally, the outer diameter of the spiral screw 5a is formed to correspond to the outer diameter of the excavated hole, and the outer peripheral end of each stirring blade is projected to a length approximately equal to the outer diameter.

The process of excavating an excavation hole H in a predetermined ground work using such a rod auger 5 will be explained with reference to FIGS. 3, 4, and 5.

First, by rotating the rod motor 4, the rod auger 5 suspended from the rod motor 4 is rotated.
starts rotating, and as the rod auger 5 rotates, the digging blade 5d fixed to the lower end of the rod auger 5 starts digging.

The excavated earth and sand is moved vertically by a spiral screw 5a, crushed and stirred by a forward stirring blade 5b, and is further crushed and stirred by being subjected to a pressing force in the opposite direction by a reverse stirring blade 5c. be done. Further, while being moved in the vertical direction by the upper spiral screw 5a, stirring can be repeated by each of the stirring blades 5b and 5c further above. Therefore, the earth and sand in the excavated hole H gradually changes from a lumpy state to fine-grained earth and sand.

During the excavation process, pressure water is ejected from the tip of the rod auger 5 via the grouting device 6 and the grouting hose 7. Therefore, the stirred earth and sand are mixed with the ejected water, and the inside of the excavation hole H is filled with mud. Excavation continues in this state filled with mud, and when the tip of the rod auger 5 reaches a predetermined depth, the inside of the excavated hole H is filled with well-stirred mud. Therefore, the wall of the drilled hole H is pushed by this mud.
Because of this, the excavated hole H will not collapse.

Further, since the rod auger 5 of the present invention is formed with the spiral screw 5a, the drilled hole H is formed to have a predetermined diameter corresponding to the outer diameter of the spiral screw 5a.

After excavation to a predetermined depth is completed, root solidifying liquid C is injected from the tip of the rod auger 5. This root solidifying liquid C is pumped from the grouting device 6 through the grouting hose 7, and in this example, it is composed of cement milk with a rich water:cement ratio of about 60%. After this root hardening liquid C is completely injected, this root hardening liquid C is stirred by the rod auger 5, so that the root hardening liquid C is supported at the lower end of the excavated hole H! It is mixed with excavated soil and the like existing in lHa, and a fill cement-like root hardening bulb S is constructed.

Supported by hardened bulb S, I? After being effectively constructed in tHa, the rod auger 5 is gradually pulled up, and during the lifting process, a pile circumferential fixing liquid with a water:cement ratio of 70% is injected from the tip of the rod auger 5. Therefore, the injected pile circumferential fixing liquid becomes mixed with the earth and sand in the excavated hole H.

The excavated hole H is completed in this way, and when the lower end of the excavated hole H is filled with the root hardening bulb S and the upper part is filled with the pile circumferential fixing liquid, from above this excavated hole H. ,
A concrete or steel pipe pile 8 suspended by a hanging cap 9 is sunk into the excavated hole H under its own weight. (FIGS. 6 and 7) In the present invention, a concrete pile 8 shown in FIG. 8 is used, and a pair of supporting iron plates 8b are welded to a flange 8a portion of the upper end surface of this pile 8. This support iron plate 8b is formed into a rectangular plate shape and protrudes toward the outer circumference of the pile 8. On the other hand, at the lower end of the pile 8, a lower end fitting 10 is welded to a flange 8c at the lower end of the pile 8. This lower end fitting 1
A window hole 10a is bored in the hole 10a, and a blade piece 10b extending inward from the window hole 10a is provided.

Furthermore, three projecting pieces 10C are welded to the lower outer periphery of the lower end fitting 10.

When such a pile 8 is placed under its own weight in the excavation hole H, the suspension cap 9 is rotated, so that the pile 8 can be rotated completely, and the lower end fitting 10 at the lower end of the pile 8 is attached to the support layer H of the excavation hole H.
It can fit completely into the hardening bulb S in a. In this case, the root hardening liquid C forming the root hardening bulb S in the root hardening bulb S enters into the lower end fitting 10 through the window hole 10a of the lower end fitting 10, and the blade piece 1
0b, and the root solidifying liquid C is pushed up into the hollow part of the pile 8. Therefore, the room-closing effect of the lower end of the pile is increased, and the lower end of the pile 8 is effectively fitted and integrated into the hardening bulb S. Therefore, the supporting force at the tip of the pile 8 can be greatly increased.

On the other hand, the supporting iron plate 8b at the upper end of the pile 8 is rotated by the hanging cap 9, so that it bites into the hole wall at the upper part of the excavated hole H and is fixed to the hole wall of the excavated hole H. Therefore,
The pile 8 is not lowered beyond a predetermined position, and the pile 8 is fixed in the excavated hole H at an effective position. At this time, the pile circumferential fixing liquid is fixed in the hollow part of the pile 8 and its outer circumference, and the root hardening bulb S and the pile circumferential fixing liquid are solidified, so that the pile 8 has a reliable tip bearing capacity. It is fixed in the excavated hole H in the state obtained (see Figs. 6 and 7).

In this way, in the pile burying method of this example, since the special rod auger 5 is used in the process of excavating the excavated hole H, there is no need to repeatedly move the rod auger 5 in the vertical direction, and the rod auger can be used in a short time. By rotating the auger, it is possible to obtain effectively granular agitated soil, and the inside of the excavation hole H can be turned into mud at an early stage. Furthermore, the pile 8 to be sunk in the excavated hole H is secured to the pile 8 by a lower end metal fitting 10 at its lower end.
The effect of closing the tip of the pile 8 is increased, the tip supporting force is strengthened, and the support iron plate 8b fixed to the upper end of the pile 8 is fixed at a predetermined position in the excavated hole H. It can be fixed in the drilled hole H.

(Effects of the Invention) The pile burying method of the present invention allows rotation of a cylindrical rod auger having a plate-shaped stirring blade and a spiral screw on the outer wall surface, and excavates and stirs the soil while moving the rod auger. Pressurized water is injected from the tip of the rod auger to turn the excavated soil into mud, and an excavated hole filled with muddy water of a predetermined depth is created at the site where the pile is to be buried. After injecting the formulated root-hardening solution and stirring the soil and root-hardening solution in the support layer with the rod auger to prevent soil-cement-like root-hardening bulbs from building up in the support layer, the tip of the rod auger is The rod auger is pulled up from the excavation hole while extracting the fixing liquid around the pile, and then the hollow pile having a support iron plate on the upper end is lowered into the excavation hole under its own weight, and the lower end of the pile is rotated. The pile is integrated into the root-hardening bulb, and the upper end of the pile is fixed to the upper part of the excavation hole via a support iron plate, which reduces the work time and provides a solid foundation within the excavation hole. This has the effect of allowing the pile to be sunk and fixed while being supported by the pile.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of an apparatus for carrying out the burying method of the present invention, Fig. 2 is a partially detailed view of a rod auger, and Figs. 3 to 7 are process states showing an example of the burying method of the present invention. Figure, 8th
The figure is an overall perspective view of the pile to be buried. 1... Excavator 4... Auger motor 5
... Rod auger 5a ... Spiral screw 5b, 5c ... Stirring blade 6 ... Grout device 8
...Pile 8b...Support iron plate 9...Hanging cap 10...Lower end fitting 10a...Window hole 10b...
・Blade piece H...Drilling hole C...Root solidification liquid
D...Pile circumference fixing liquid Patent applicant Taiyo Concrete Co., Ltd. Head office agent Patent attorney Yoshi Shimizu
Figure 8 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7

Claims (1)

[Scope of Claims] Rotating a cylindrical rod auger having a plate-like stirring blade and a spiral screw on the outer wall, excavating and stirring soil, and injecting pressurized water from the tip of the rod auger, The excavated earth and sand are turned into mud, and an excavation hole filled with muddy water of a predetermined depth is made at the site where the pile is planned to be buried, and a richly mixed root solidifying solution is injected from the tip of the rod auger into the support layer at the lower end of the excavation hole. , After stirring the soil and root hardening solution in the support layer with the rod auger to build soil cement-like root hardening bulbs in the support layer, while extracting the pile circumference fixing solution from the tip of the rod auger. The rod auger is pulled up from the excavated hole, and then a hollow pile having a support iron plate on the upper end surface is lowered under its own weight into the excavated hole, and the lower end of the pile is inserted into the root hardening bulb by rotating the pile. 1. A method for burying piles, which comprises integrating the piles and fixing the upper ends of the piles in the upper part of the excavated hole via a support iron plate.