JPS61134426A - Method of burying pile - Google Patents

Abstract

PURPOSE:To facilitate disposal of surplus coil, by a method wherein, before a pile hole is excavated, an amount of soil being surplus when a precast pile is inserted into the pile hole is calculated, a ground improving agent is mixed, and the precast pile is inserted. CONSTITUTION:Before a pile hole is excavated by means of an excavating device, an amount of soil discharged is previously calculated. With the excavating device 16 being actuated, a pile hole 23 is excavated down to a given depth, and oil in a condition, in that it is loosened within the hole 23, is discharged to a ground surface with the aid of a screw. After a previously calculated amount of soil 22 is discharged to a ground surface, the excavating device 16 is lifted up, and a ground improving agent is mixed from the forward end thereof. Thereafter, a precast pile 26 is inserted into the pile hole 23 to complete a work. Since soil discharged from the pile hole 23 is free of mixture of the ground improving agent, the above mentioned process facilitates disposal of the soil.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a construction method for embedding and fixing piles used for building foundations in underground excavated holes, and in particular, to a construction method that eliminates the need for existing piles. This invention relates to a method of embedding piles using a vibration method and ensuring reliable integration with the ground.

(Conventional technology) Traditionally, when constructing buildings on soft ground, concrete piles, cast-in-place piles, etc. have been constructed to stabilize the ground and to increase the supporting load. It is common practice to construct a building after constructing a concrete foundation and pouring a cloth foundation on top of it.

In addition, in the case of houses and small-scale buildings, since the weight of the building is small, it is recommended to use an earth drill or auger instead of driving existing concrete piles directly into the ground. A common practice is to drill pile holes in the ground, mix soil conditioners with the soil in the holes, and harden the mixture to increase the load-bearing capacity of the soil. many.

The ground strengthening method described above is generally called the ground stabilization method, and the load-bearing strength of the pile is lower than that of the method of driving ordinary prefabricated piles directly into the ground. Despite this, it is a construction method that is often used in residential areas because it can reduce the effects of noise and vibration.

The above-mentioned construction method uses a drilling member such as an earth drill as described in Japanese Patent Application Laid-Open No. 56-153012, etc., to drill a hole of a predetermined size in the ground. A soil improvement agent is ejected from a nozzle formed at the tip of the soil and mixed with the soil. Cement milk or other chemicals are used as the soil improvement agent. .

However, with the conventional ground improvement method,
Although the amount of soil inside the pile hole increases due to excavation,
All of this has been mixed with soil improvement agents, and the current situation is that it is difficult to dispose of the hardened soil after construction.

In addition, when forming a foundation using ready-made piles such as concrete friction piles with triangular cross sections, excavate with something like an earth drill and pour cement milk etc. into the hole. Although the piles are then driven in with a hammer, the pile holes drilled with an earth drill have the same cross-section, whereas the conventional friction piles It is formed so that it becomes gradually thinner as it reaches its tip.

Therefore, depending on this construction method, a relatively large space is formed around the pile with a triangular cross section, but since the cement milk poured into the hole is liquid and highly fluid, the pile It is not possible to reliably consolidate the inside of the hole, and sometimes the soil around the pile collapses or loosens, which causes the ground around the pile to cave in, especially when Buildings with unsteady foundations, such as adjacent concrete block walls or wooden buildings, may be affected by the ground sinking, and it is difficult to take countermeasures. .

(Problems to be Solved by the Invention) The present invention solves the drawbacks of conventional construction methods as described above. By calculating the amount of soil and removing the excess soil before mixing the soil improvement agent, it is easier to dispose of the remaining soil, and it is also possible to drive ready-made piles into the muddy soil that has been mixed with the soil improvement agent. The purpose is to consolidate the muddy soil in the pile and make it possible to integrate the area around the pile hole with the pile itself.

(Means and effects for solving the problems) The present invention has the following features:
The excavating device is constructed by providing an excavating portion and a nozzle at the tip of a rod, forming a rod of a predetermined length on the rod, and integrally connecting a screw onto the rod.

When excavating pile holes, the amount of increase in soil due to excavation,
Calculate in advance the amount of soil added by mixing with the soil conditioner, the volume of the prefabricated piles to be driven later, the depth of the cloth foundation, etc., and then calculate the amount of soil to be removed from the pile hole. During excavation, the soil is discharged to the ground using a screw, and the soil remaining in the hole is then mixed with the ground improvement agent.

After that, prefabricated piles such as concrete piles are driven in, and the muddy soil formed by mixing and stirring a soil improvement agent is consolidated and surrounded around the prefabricated piles. The pile and the ground are bonded together to improve the strength of the pile and to prevent loosening of the ground around the pile.

(Example) The structure of the pile and excavation device of the present invention will be explained according to the illustrated embodiment. As shown in FIG. It is provided so as to be movable up and down along the post 5.

The trolley 1 is provided with a wire 4, by which a wire 4 is wound, passes through an upper member 6 equipped with a pulley, and suspends the head member 1o. The slider 12 of the head member 10 is guided by a guide rod 11 provided along the post 5, and is guided by a screw 16 and an excavation part 18.
A drive device 13 such as a hydraulic motor is provided to drive the.

ing.

The excavating device of the present invention is composed of a screw 16 connected to the drive device 13 as described above, a rod 17 connected to the lower part of the screw 16, and an excavating section 18. A large number of stirring blades 18a having the shape of are formed in a protruding state.

The above-mentioned rod, screw, and excavation part each have a hole formed in the center of their shaft, and the slurry etc. supplied from the slurry inlet 14 in the upper part is passed through the hole formed in each member. It is ejected from a nozzle 19 formed under the excavation part 18. Therefore, cement milk or the like used as a soil improvement agent is mixed with water and other chemicals in a mixer 7, supplied to an injection port 14 via a hose 9 by a pump 8, and passed through a hollow screw or rod to a nozzle. The water is ejected from the soil 19, and is mixed and stirred with the soil by the stirring blades 18a.

In the device of the present invention, the screw 16 has spiral wings 16 around a hollow shaft 16a, as shown in FIG.
b is formed in a protruding state, and this screw 16
The connection between the rod 17 and the rod 17 is as shown in FIG.
It is inserted into the hole below and fixed with a screw 16c.

Further, the rod 17 and the excavated portion 18 can be connected by the above-mentioned fixing method, and the shaft members can be connected using other methods. Of course, this is also possible.

Further, a rest stop 15 is formed on the post 5 and is connected to the head member 10 via a rope or the like and configured to move the post 5 up and down over a predetermined range to prevent swinging of the rod 17, etc. However, this touch stopper 1
5 will be opened so as not to interfere with the screw 16 when it comes to engage with it.

Next, the operation when excavating a pile hole using the apparatus of the present invention will be explained based on FIG. 4.

First, as shown in FIG. 4(a), the post 5 is positioned at the location where the pile foundation work is to be performed, the drive device 13 is activated, and excavation of the pile hole 23 is started. As shown in the same figure (b), the soil 21 excavated by the excavation unit 18 is
While the excavated portion 18 and the rod 17 are submerged under the ground @ 20, they are in a state of being stirred and loosened in the pile hole 23, and are raised slightly upward.

Next, as shown in (c), the screw 16 is inserted into the hole 23.
Once inside, the soil loosened within the pile hole 23 will be discharged onto the ground by the screw. Then, when drilling the hole 23 to a predetermined depth, the rotation of the screw 16 causes an amount of ±22, which is calculated in advance, to be discharged to the ground.

As shown in Figure (D), the amount of soil discharged is equal to the amount of muddy soil 24 formed by mixing and stirring a ground improvement agent into ±21 excavated in the pile hole 23. This is done so that only a predetermined amount remains.

For example, the amount of soil left in the pile hole 23 is determined by seven factors: the size of the hole excavated by the excavator and the coefficient of expansion of the soil loosened by the excavation of the hole. is the soil minus 1. In addition, in this calculation, the amount of soil left in the pile hole will naturally take into account the increase in soil volume due to the mixing of the ground improvement agent.

In the construction method of the present invention, the pile hole 23 of a predetermined depth is excavated in the state shown in (c), and when the calculated amount of soil has been removed, the excavation part 18 is rotated and pulled. At the same time, the soil improvement agent is jetted from the nozzle 18a, and the soil improvement agent of ±21 is mixed. In this mixing and agitation, if mixing only once is insufficient, the excavated part 18 is immersed into the muddy soil 24 again, and the supply of the ground improvement agent is continued to obtain a predetermined amount of soil. Mix modifier to ±21.

Therefore, in the construction method of the present invention, the amount of muddy soil mixed with the ground improvement agent and left in the pile hole 23 is (
As shown in d), the depth is lower than the level of the ground 20 by L.

Due to the erosion, prefabricated concrete piles 2
6 will be driven in, but the length of this pre-made pile is the same as the pile hole 2.
In the same way as the depth in step 3, it is determined according to the depth H of the cloth foundation to be formed on top of it, by slightly driving the prefabricated pile 26 and fixing its tip to the bottom of the pile hole. There is.

The prefabricated pile 26 used in the present invention is made of concrete and has a triangular cross section with joints 27 protruding at predetermined intervals.The pile 26 is placed in muddy soil. It is fixed at a predetermined depth by driving it in with a hammer or the like.

When driving a ready-made pile into this pile hole 23, the i!
! The muddy ±24 with poor mobility is consolidated and wraps around the pile 26 without any gaps, and the ground improvement agent hardens in that state.

Therefore, in the construction method of the present invention, it is ensured that the soil around the pile hole 23 does not collapse or loosen until the muddy soil hardens after driving the prefabricated pile. Prevented.

Furthermore, in the construction method of the present invention, drilling of pile holes, mixing of soil improvement agent, and driving of existing piles are performed in a very short period of time, and only the soil required for forming piles is used. is left in the pile hole 23, and the excess soil is removed before being mixed with the soil improvement agent. Because it is not, it becomes easier to dispose of the soil.

In addition, the ground improvement agent used in the construction method of the present invention is mainly a mixture of cement, water, foaming agent, etc., but it is also possible to mix a hardening accelerator, etc., or change the amount of cement, water-cement, etc. Naturally, the ratio should be determined according to the properties of the soil and the design strength of the pile.

In addition, as mentioned above, in the construction method of the present invention, the upper part of the pile is formed in a state that is aligned with the lower surface of the cloth foundation, so it is easier to drive the pile by digging the ground and Concrete for the foundation can be poured immediately with the pile heads exposed.As with the conventional construction method, the pile heads are scraped from the ground to a specified depth, and then concrete is poured. There is no need to spend extra effort such as pouring concrete for a cloth foundation.

(Effects of the Invention) Since the construction method of the present invention is as described above, the driving of prefabricated piles can be done very easily without photographing or generating noise, etc. The strength of the formed pile is reduced because the space between the surrounding area of the pile and the wall of the pile hole is filled with hardened soil in a consolidated state, and the pile body and the ground are formed integrally. It is possible to secure sufficient capacity.

In addition, since the soil that has been removed from the pile holes in advance has not been mixed with soil conditioners, it can be used again in other locations, and unlike conventional construction methods, it is possible to use hardened soil. No situation arises that makes disposal difficult.

Furthermore, in the construction method of the present invention, the soil improvement agent is mixed only with the soil necessary for forming the piles, thereby reducing the amount of soil improvement agent used. This makes it possible to reduce installation costs.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram of the equipment used in the construction method of the present invention;
3 is an explanatory diagram showing the configuration of the screw and the connection part between the screw and the rod, and FIG.
(E) is an explanatory diagram showing the steps of the pile driving method of the present invention. Reference numeral 1 in the figure...Dolly, 2...Support arm, 3.
...Winch, 4...Wire, 5...
...Post, 6...Top member, 7...
・Mixer, 8...Pump, 9...Hose, 10...Head member, 11...Guide rod, 12...Slider, 13...
... Drive device, 14 ... Inlet, 15 ...
... Stopper, 16 ... Screw, 17 ...
...Rod, 18...Drilling part, 19...
... Nozzle, 20 ... Ground, 21 ...
・Excavated soil, 22...Ejected soil, 23
...Pile hole, 24...Muddy soil, 25.
...Hardened soil, 26 ...Prefabricated pile, 27
······section. --Ko

Claims (2)

[Claims] (1) When excavating pile holes, calculate in advance the amount of soil added due to excavation and mixing with soil conditioner, the depth of the cloth foundation, the volume of the piles to be buried later, etc., and remove soil that is not needed for pile formation. , when excavating the pile hole, first remove it, then mix the soil improver with the soil in the hole, and then consolidate the muddy soil mixed with the soil improver, A pile embedding method characterized by embedding prefabricated piles therein. (2) An excavation part for performing excavation and a nozzle for spouting a ground improvement agent are provided at the tip of the rod, and a screw is further provided thereon via a rod of a predetermined length,
When excavating a pile hole in the ground using a drilling device that is made up of these parts, the screw formed above the excavation part removes excess soil that is not needed for pile formation, and then the nozzle removes the soil from the ground. The pile according to claim 1, characterized in that the improving agent is injected and mixed with the soil to compact the muddy soil, and the prefabricated pile is embedded therein. embedding method.