JPS62242011A - Method and apparatus for constructing shallow ground-improving pile - Google Patents

Abstract

PURPOSE:To obtain a ground-improving pile to consolidate the surrounding ground by a method in which a conical auger is formed on the lower end of a pressing pipe, a pile pit is excavated by the auger, and a filling material is forced from the lower end of the pipe into the pile pit. CONSTITUTION:A weight 41 is put on soft ground 40 to prevent the lift-up of the surface soil, and a pressing pipe 15 is penetrated into the ground 40 while being turned. In this case, a pile pit 51 whose surrounding is consolidated is formed by the conical portion 35 of the auger 29. When the pit 51 reaches a given depth, the auger 29 is pulled up while being turned reversely, and a mixture 55 of cement and sand is charged from the lower end of the pipe 1 into the pit 51. The surrounding ground of the pile so formed can be consolidated by the pile and the bearing capacity of the pile can be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a shallow ground improvement pile construction method and its apparatus.

(Conventional technology) When the ground is soft and there is no bearing capacity for the structure, conventional methods such as replacement earth construction method and pile foundation construction method are used.

Soft ground is being strengthened using methods such as chemical injection, consolidation methods (preload method, sand compaction method), and water drainage method.

[Problem that the invention seeks to solve]

However, considering the recent construction environment, these construction methods have the following problems.

In other words, with the earth displacement method, the impact of ground subsidence on surrounding facilities (houses, etc.) due to excavation, the difficulty of disposing of excavated soil,
There are problems such as an increase in construction costs due to earth retaining work and a large amount of construction costs due to the large amount of replacement earth purchased.

Pile foundation construction methods are often vibration-free and noise-free due to the construction environment, making it difficult to dispose of waste soil, causing water pollution due to the use of hole wall protection agents, and taking reaction force only with piles. Therefore, there are problems such as large-scale construction and relatively high construction costs.

The chemical injection method has problems such as contaminating groundwater quality, unclear injection amount, unreliable ground improvement effect, and high construction costs.

In the Bre Road construction method, a large amount of soil is required for pre-filling, and it takes time to consolidate.On the roadside, when pre-filling, it is necessary to include adjacent land, and it is necessary to include the adjacent land, and it is necessary to include the adjacent land in areas where facilities (houses), etc. are close to each other. However, there are problems such as impossibility of construction.

In the sand compaction method, sand is injected into the soft ground, so the surrounding ground is compacted, but the sand pile itself does not have much bearing capacity, so the ground is improved by the compaction layer itself, and the overall area is Ground bearing capacity cannot be expected unless compaction is taken into account, and the construction equipment is large-scale, making it difficult to use unless the scale of construction is large, and construction costs will be high.
There are problems such as vibration occurring when sand is pressed in.

The water construction method promotes consolidation settlement by pumping up groundwater, so it takes time to become effective, it affects surrounding facilities (houses, etc.), and there are problems with the treatment of the pumped water.

[Purpose of the invention]

The present invention was made in order to solve the above-mentioned problems, and an object of the present invention is to provide a shallow ground improvement pile method and its device that can sufficiently strengthen soft ground without causing environmental destruction. shall be.

[Means for solving problems]

The shallow ground improvement pile method according to the present invention involves inserting a conical auger, which has drill wings on the outer periphery and is formed at the tip of a push-in pipe, into the shallow ground of soft ground. A hole is formed with the surrounding area consolidated, and after the hole reaches a predetermined depth, a filling material is press-fitted into the hole from the tip of the push-in pipe while pulling out the auger, and the amount of subsidence displacement with the surrounding ground is adjusted. By forming uniform friction piles, an uneven subsidence prevention layer is created.

Further, the ground improvement pile device of the present invention is a ground improvement pile device in which an auger is formed at the tip of a push-in pipe, in which a screw conveyor is disposed within the push-in pipe, and
A valve that opens from the inside to the outside is arranged at the tip opening of the push-in pipe, and the auger is composed of a cylindrical part and a conical part formed above and below the cylindrical part, and the auger is attached to the lower conical part. A drill blade is installed to convert the rotational force of the machine into propulsion force, and
The upper conical part is equipped with drill blades to consolidate soil whose walls have collapsed during extraction.

[Action of the invention]

In the shallow ground improvement pile method of the present invention, a conical auger is inserted into a shallow part of the soft ground to form a hole with a consolidated periphery, and a filling material is press-fitted into the hole. Since friction piles are formed, the surrounding ground and friction piles share the load differently, but the amount of settlement is uniform, creating an uneven settlement prevention layer, thereby creating a ground that can sufficiently withstand the overburden load. can be formed.

In addition, in the ground improvement pile device of the present invention, a screw conveyor is placed inside the push-in pipe, and a valve that opens from the inside to the outside is placed at the tip opening of the push-in pipe, so that filling material can be easily removed when the auger is pulled out. Can be supplied into the hole.

In addition, the auger is composed of a cylindrical part and a conical part formed above and below this cylindrical part, and the lower conical part is equipped with a drill blade that converts the rotational force of the auger into propulsive force. The auger can be easily inserted into the ground while forming a consolidated layer around it, and a drill blade for consolidation is provided on the upper conical part, so soil that has collapsed on the hole wall can be re-attached to the hole wall. It can be pressed and there is no soil removal.

[Embodiments of the invention]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, one embodiment of the present invention will be described in detail without being shown in the drawings.

FIG. 1 shows an embodiment of the soil improvement pile device of the present invention, and in the figure, reference numeral 11 indicates a base machine having a main pillar 13. At the upper end of the main column 13, a hopper 17 formed at the upper end of the push-in pipe 15 is connected to the hanging wire 1.
It is held suspended by 9. The push-in pipe 15 is vertically movable by a cylinder 21 arranged on the main column 13.

In the ground improvement pile devices of the first and second embodiments, a screw conveyor 25 rotated by a drive device 23 is disposed inside the push pipe 15. A valve 27 that opens from the inside to the outside is arranged at the tip opening of the push-in pipe 15. An auger 29 is arranged at the tip of the push pipe 15. As shown in FIG. 2, this auger 29 is composed of a cylindrical portion 31 and conical portions 33, 35 formed above and below this cylindrical portion 31. The lower conical part 35 has a drill blade 3 that converts the rotational force of the auger 29 into propulsive force.
7, and a drill blade 38 is formed on the upper conical portion 33. Note that the push-in pipe 15 is rotatable by a rotary power head 39.

Figures 3 and 4 show a weight 41 that prevents the topsoil from rising when the auger 29 is pushed into soft ground 40.
This weight 41 is a half body 43.45
A through hole 49 into which the auger 29 is inserted is formed in the center of the weight 41.

Using the soil improvement pile device configured as described above, the shallow soil improvement pile construction method of the present invention is carried out as described below.

That is, as shown in FIG. 5, two weights 41 are placed on the soft ground 40, and the auger 29
Dissipation of stress due to the heaving of the topsoil when pushed into 40 is prevented. After that, with the push-in pipe 15 being rotated by the rotary power head 39, the cylinder 2
1, it is inserted into the soft ground mdQ. At this time, the conical portion 35 of the auger 29 forms a hole 51 whose periphery is compacted. Further, since the drill blades 37 are arranged on the auger 29, the rotational force of the auger 29 becomes a thrust, making it easy to insert the push pipe 15 into the soft ground 40, and making it possible to downsize the base machine 11. This hole hole 5
1 reaches a predetermined depth, a valve 27 formed at the tip of the push-in pipe 15 is opened. Thereafter, as shown in FIG. 6, the screw conveyor 25 is rotated while the auger 29 is reversely rotated and pulled out, and the filling material (for example, a mixture of cement and sand) 53 in the hopper 17 is transferred to 25, the hole 5 is inserted from the tip of the push-in pipe 15.
It is press-fitted into 1. Also during this extraction, the conical portion 33 at the top of the auger 29 applies reverse rotation, so that a consolidated layer is formed again around the soft ground 40, thereby preventing the ground around the hole wall from loosening. And push pipe 15
After pulling out, by leaving it for a certain period of time, the filling material 53
is solidified, and a friction pile 55 as shown in FIG. 7 is formed.

That is, in the ground improvement pile construction method configured as described above, by inserting the conical auger 29 into the soft ground 40, a hole 51 with a consolidated periphery is formed, and
Since the filling material 53 is press-fitted into the hole 51 to form the friction pile 55, the surrounding ground and the friction pile 55 share the load differently, but the amount of settlement displacement is uniform, and it can sufficiently withstand the overburden load. It is possible to form a solid foundation.

In addition, in the ground improvement pile device configured as described above, the screw conveyor 25 is arranged inside the pushing vibrator 15, and the valve 27 that opens from the inside to the outside is arranged at the tip opening of the pushing pipe 15, so that the auger 29 The filling material 53 can be easily supplied into the hole 51 when it is pulled out. In addition, the auger 29 is composed of a cylindrical portion 31 and conical portions 33 and 35 formed above and below the cylindrical portion 31, and the lower conical portion 35 is provided with a drill that converts the rotational force of the auger 29 into propulsive force. Since the wings 37 are provided, the auger 29 can be easily inserted into the ground while forming the consolidation H around the hole 51.

Furthermore, according to the shallow ground improvement pile construction method and its apparatus configured as described above, excavated soil and waste soil are not generated, so that the treatment of these soils is not necessary. There will be no impact on surrounding buildings as there will be no excavation. No water pollution. By consolidating the hole wall, the ground around the pile is consolidated and the bearing capacity is increased. For example, sufficient vertical reaction force can be obtained by making mortar piles, and resistance to buckling can be increased by incorporating short iron wires. It has advantages such as vibration-free and noise-free construction method.

In the present invention, the friction pile refers to a pile installed in an uneven settlement prevention layer in a soft ground layer, as shown in FIG.

〔Effect of the invention〕

As described above, the present invention has the advantage that it is possible to provide a ground improvement pile method and an apparatus thereof that can sufficiently strengthen soft ground without causing environmental destruction.

[Brief explanation of drawings]

Fig. 1 is a side view showing one embodiment of the soil improvement pile device of the present invention, Fig. 2 is a partial vertical cross-sectional view showing details of the auger part in Fig. 1, Figs. 3 and 4! J is a top view and a side view of the weight, Figures 5 to 7 are explanatory diagrams showing one embodiment of the shallow ground improvement pile construction method of the present invention, and Figure 8 is an explanatory diagram of the friction pile in the present invention. . 15... Push pipe, 25... Screw conveyor,
27... Valve, 29... Auger, 31... Cylindrical part,
33.35...Conical part, 37°38...Drill blade,
51... Hole hole, 53... Filling material, 55... Friction pile. #43 Figure 1 Figure 4

Claims (2)

[Claims] (1) By inserting a conical auger, which has a drill blade on the outer periphery and is formed at the tip of a push pipe, into a shallow part of the soft ground, a hole is formed with the surrounding area consolidated; After this hole reaches a predetermined depth, while pulling out the auger, filler material is press-fitted into the hole from the tip of the push-in pipe, and a friction pile is created so that the amount of subsidence is uniform with the surrounding ground. A shallow ground improvement pile construction method that is characterized by creating an uneven settlement prevention layer by forming piles. (2) In a ground improvement pile device in which an auger is formed at the tip of a push-in pipe, a screw conveyor is arranged inside the push-in pipe, and a valve that opens from the inside to the outside is arranged at the tip opening of the push-in pipe, The auger is composed of a cylindrical part and a conical part formed above and below the cylindrical part, and the lower conical part has a drill blade that converts the rotational force of the auger into propulsive force, and the upper conical part has a drill blade that converts the rotational force of the auger into propulsive force. A ground improvement pile device characterized in that it is equipped with drill wings for consolidating soil whose hole walls have collapsed during extraction.